Update On Sat Jan 27 19:40:48 CET 2024

browser/components/BrowserContentHandler.sys.mjs

@@ -1112,13 +1112,6 @@ nsDefaultCommandLineHandler.prototype = {
     var urilist = [];
     var principalList = [];
 
-    if (cmdLine && cmdLine.state == Ci.nsICommandLine.STATE_INITIAL_LAUNCH) {
-      // Since the purpose of this is to record early in startup,
-      // only record on launches, not already-running invocations.
-      Services.telemetry.setEventRecordingEnabled("telemetry", true);
-      Glean.fogValidation.validateEarlyEvent.record();
-    }
-
     if (AppConstants.platform == "win") {
       // Windows itself does disk I/O when the notification service is
       // initialized, so make sure that is lazy.

browser/components/aboutwelcome/content-src/aboutwelcome.scss

@@ -610,19 +610,19 @@ html {
 
               .additional-cta {
                 margin: 0;
-              }
 
-              &.cta-link {
-                @include text-link-styles;
+                &.cta-link {
+                  @include text-link-styles;
 
-                padding: 0;
-                font-weight: normal;
-              }
+                  padding: 0;
+                  font-weight: normal;
+                }
 
-              &.secondary {
-                &:hover,
-                &[open] {
-                  background-color: var(--in-content-button-background-hover);
+                &.secondary {
+                  &:hover,
+                  &[open] {
+                    background-color: var(--in-content-button-background-hover);
+                  }
                 }
               }
             }

browser/components/aboutwelcome/content/aboutwelcome.css

@@ -1390,7 +1390,7 @@ html {
 .onboardingContainer .screen[pos=split] .section-main .main-content .action-buttons .additional-cta-box .additional-cta {
   margin: 0;
 }
-.onboardingContainer .screen[pos=split] .section-main .main-content .action-buttons .additional-cta-box.cta-link {
+.onboardingContainer .screen[pos=split] .section-main .main-content .action-buttons .additional-cta-box .additional-cta.cta-link {
   background: none;
   text-decoration: underline;
   cursor: pointer;
@@ -1398,18 +1398,18 @@ html {
   padding: 0;
   font-weight: normal;
 }
-.onboardingContainer .screen[pos=split] .section-main .main-content .action-buttons .additional-cta-box.cta-link:hover {
+.onboardingContainer .screen[pos=split] .section-main .main-content .action-buttons .additional-cta-box .additional-cta.cta-link:hover {
   color: var(--link-color-hover);
 }
-.onboardingContainer .screen[pos=split] .section-main .main-content .action-buttons .additional-cta-box.cta-link:active {
+.onboardingContainer .screen[pos=split] .section-main .main-content .action-buttons .additional-cta-box .additional-cta.cta-link:active {
   color: var(--link-color-active);
 }
 @media (prefers-contrast) {
-  .onboardingContainer .screen[pos=split] .section-main .main-content .action-buttons .additional-cta-box.cta-link:active {
+  .onboardingContainer .screen[pos=split] .section-main .main-content .action-buttons .additional-cta-box .additional-cta.cta-link:active {
     text-decoration: none;
   }
 }
-.onboardingContainer .screen[pos=split] .section-main .main-content .action-buttons .additional-cta-box.secondary:hover, .onboardingContainer .screen[pos=split] .section-main .main-content .action-buttons .additional-cta-box.secondary[open] {
+.onboardingContainer .screen[pos=split] .section-main .main-content .action-buttons .additional-cta-box .additional-cta.secondary:hover, .onboardingContainer .screen[pos=split] .section-main .main-content .action-buttons .additional-cta-box .additional-cta.secondary[open] {
   background-color: var(--in-content-button-background-hover);
 }
 .onboardingContainer .screen[pos=split] .section-main .main-content .action-buttons.additional-cta-container {

browser/components/firefoxview/OpenTabs.sys.mjs

@@ -0,0 +1,398 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * This module provides the means to monitor and query for tab collections against open
+ * browser windows and allow listeners to be notified of changes to those collections.
+ */
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  DeferredTask: "resource://gre/modules/DeferredTask.sys.mjs",
+  EveryWindow: "resource:///modules/EveryWindow.sys.mjs",
+  PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.sys.mjs",
+});
+
+const TAB_ATTRS_TO_WATCH = Object.freeze(["image", "label"]);
+const TAB_CHANGE_EVENTS = Object.freeze([
+  "TabAttrModified",
+  "TabClose",
+  "TabMove",
+  "TabOpen",
+  "TabPinned",
+  "TabUnpinned",
+]);
+const TAB_RECENCY_CHANGE_EVENTS = Object.freeze([
+  "activate",
+  "TabAttrModified",
+  "TabClose",
+  "TabOpen",
+  "TabSelect",
+]);
+
+// Debounce tab/tab recency changes and dispatch max once per frame at 60fps
+const CHANGES_DEBOUNCE_MS = 1000 / 60;
+
+/**
+ * A sort function used to order tabs by most-recently seen and active.
+ */
+export function lastSeenActiveSort(a, b) {
+  let dt = b.lastSeenActive - a.lastSeenActive;
+  if (dt) {
+    return dt;
+  }
+  // try to break a deadlock by sorting the selected tab higher
+  if (!(a.selected || b.selected)) {
+    return 0;
+  }
+  return a.selected ? -1 : 1;
+}
+
+/**
+ * Provides a object capable of monitoring and accessing tab collections for either
+ * private or non-private browser windows. As the class extends EventTarget, consumers
+ * should add event listeners for the change events.
+ *
+ * @param {boolean} options.usePrivateWindows
+              Constrain to only windows that match this privateness. Defaults to false.
+ * @param {Window | null} options.exclusiveWindow
+ *            Constrain to only a specific window.
+ */
+class OpenTabsTarget extends EventTarget {
+  #changedWindowsByType = {
+    TabChange: new Set(),
+    TabRecencyChange: new Set(),
+  };
+  #dispatchChangesTask;
+  #started = false;
+  #watchedWindows = new Set();
+
+  #exclusiveWindowWeakRef = null;
+  usePrivateWindows = false;
+
+  constructor(options = {}) {
+    super();
+    this.usePrivateWindows = !!options.usePrivateWindows;
+
+    if (options.exclusiveWindow) {
+      this.exclusiveWindow = options.exclusiveWindow;
+      this.everyWindowCallbackId = `opentabs-${this.exclusiveWindow.windowGlobalChild.innerWindowId}`;
+    } else {
+      this.everyWindowCallbackId = `opentabs-${
+        this.usePrivateWindows ? "private" : "non-private"
+      }`;
+    }
+  }
+
+  get exclusiveWindow() {
+    return this.#exclusiveWindowWeakRef?.get();
+  }
+  set exclusiveWindow(newValue) {
+    if (newValue) {
+      this.#exclusiveWindowWeakRef = Cu.getWeakReference(newValue);
+    } else {
+      this.#exclusiveWindowWeakRef = null;
+    }
+  }
+
+  includeWindowFilter(win) {
+    if (this.#exclusiveWindowWeakRef) {
+      return win == this.exclusiveWindow;
+    }
+    return (
+      win.gBrowser &&
+      !win.closed &&
+      this.usePrivateWindows == lazy.PrivateBrowsingUtils.isWindowPrivate(win)
+    );
+  }
+
+  get currentWindows() {
+    return lazy.EveryWindow.readyWindows.filter(win =>
+      this.includeWindowFilter(win)
+    );
+  }
+
+  /**
+   * A promise that resolves to all matched windows once their delayedStartupPromise resolves
+   */
+  get readyWindowsPromise() {
+    let windowList = Array.from(
+      Services.wm.getEnumerator("navigator:browser")
+    ).filter(win => {
+      // avoid waiting for windows we definitely don't care about
+      if (this.#exclusiveWindowWeakRef) {
+        return this.exclusiveWindow == win;
+      }
+      return (
+        this.usePrivateWindows == lazy.PrivateBrowsingUtils.isWindowPrivate(win)
+      );
+    });
+    return Promise.allSettled(
+      windowList.map(win => win.delayedStartupPromise)
+    ).then(() => {
+      // re-filter the list as properties might have changed in the interim
+      return windowList.filter(win => this.includeWindowFilter);
+    });
+  }
+
+  haveListenersForEvent(eventType) {
+    switch (eventType) {
+      case "TabChange":
+        return Services.els.hasListenersFor(this, "TabChange");
+      case "TabRecencyChange":
+        return Services.els.hasListenersFor(this, "TabRecencyChange");
+      default:
+        return false;
+    }
+  }
+
+  get haveAnyListeners() {
+    return (
+      this.haveListenersForEvent("TabChange") ||
+      this.haveListenersForEvent("TabRecencyChange")
+    );
+  }
+
+  /*
+   * @param {string} type
+   *        Either "TabChange" or "TabRecencyChange"
+   * @param {Object|Function} listener
+   * @param {Object} [options]
+   */
+  addEventListener(type, listener, options) {
+    let hadListeners = this.haveAnyListeners;
+    super.addEventListener(type, listener, options);
+
+    // if this is the first listener, start up all the window & tab monitoring
+    if (!hadListeners && this.haveAnyListeners) {
+      this.start();
+    }
+  }
+
+  /*
+   * @param {string} type
+   *        Either "TabChange" or "TabRecencyChange"
+   * @param {Object|Function} listener
+   */
+  removeEventListener(type, listener) {
+    let hadListeners = this.haveAnyListeners;
+    super.removeEventListener(type, listener);
+
+    // if this was the last listener, we can stop all the window & tab monitoring
+    if (hadListeners && !this.haveAnyListeners) {
+      this.stop();
+    }
+  }
+
+  /**
+   * Begin watching for tab-related events from all browser windows matching the instance's private property
+   */
+  start() {
+    if (this.#started) {
+      return;
+    }
+    // EveryWindow will call #watchWindow for each open window once its delayedStartupPromise resolves.
+    lazy.EveryWindow.registerCallback(
+      this.everyWindowCallbackId,
+      win => this.#watchWindow(win),
+      win => this.#unwatchWindow(win)
+    );
+    this.#started = true;
+  }
+
+  /**
+   * Stop watching for tab-related events from all browser windows and clean up.
+   */
+  stop() {
+    if (this.#started) {
+      lazy.EveryWindow.unregisterCallback(this.everyWindowCallbackId);
+      this.#started = false;
+    }
+    for (let changedWindows of Object.values(this.#changedWindowsByType)) {
+      changedWindows.clear();
+    }
+    this.#watchedWindows.clear();
+    this.#dispatchChangesTask?.disarm();
+  }
+
+  /**
+   * Add listeners for tab-related events from the given window. The consumer's
+   * listeners will always be notified at least once for newly-watched window.
+   */
+  #watchWindow(win) {
+    if (!this.includeWindowFilter(win)) {
+      return;
+    }
+    this.#watchedWindows.add(win);
+    const { tabContainer } = win.gBrowser;
+    tabContainer.addEventListener("TabAttrModified", this);
+    tabContainer.addEventListener("TabClose", this);
+    tabContainer.addEventListener("TabMove", this);
+    tabContainer.addEventListener("TabOpen", this);
+    tabContainer.addEventListener("TabPinned", this);
+    tabContainer.addEventListener("TabUnpinned", this);
+    tabContainer.addEventListener("TabSelect", this);
+    win.addEventListener("activate", this);
+
+    this.#scheduleEventDispatch("TabChange", {});
+    this.#scheduleEventDispatch("TabRecencyChange", {});
+  }
+
+  /**
+   * Remove all listeners for tab-related events from the given window.
+   * Consumers will always be notified at least once for unwatched window.
+   */
+  #unwatchWindow(win) {
+    // We check the window is in our watchedWindows collection rather than currentWindows
+    // as the unwatched window may not match the criteria we used to watch it anymore,
+    // and we need to unhook our event listeners regardless.
+    if (this.#watchedWindows.has(win)) {
+      this.#watchedWindows.delete(win);
+
+      const { tabContainer } = win.gBrowser;
+      tabContainer.removeEventListener("TabAttrModified", this);
+      tabContainer.removeEventListener("TabClose", this);
+      tabContainer.removeEventListener("TabMove", this);
+      tabContainer.removeEventListener("TabOpen", this);
+      tabContainer.removeEventListener("TabPinned", this);
+      tabContainer.removeEventListener("TabSelect", this);
+      tabContainer.removeEventListener("TabUnpinned", this);
+      win.removeEventListener("activate", this);
+
+      this.#scheduleEventDispatch("TabChange", {});
+      this.#scheduleEventDispatch("TabRecencyChange", {});
+    }
+  }
+
+  /**
+   * Flag the need to notify all our consumers of a change to open tabs.
+   * Repeated calls within approx 16ms will be consolidated
+   * into one event dispatch.
+   */
+  #scheduleEventDispatch(eventType, { sourceWindowId } = {}) {
+    if (!this.haveListenersForEvent(eventType)) {
+      return;
+    }
+
+    this.#changedWindowsByType[eventType].add(sourceWindowId);
+    // Queue up an event dispatch - we use a deferred task to make this less noisy by
+    // consolidating multiple change events into one.
+    if (!this.#dispatchChangesTask) {
+      this.#dispatchChangesTask = new lazy.DeferredTask(() => {
+        this.#dispatchChanges();
+      }, CHANGES_DEBOUNCE_MS);
+    }
+    this.#dispatchChangesTask.arm();
+  }
+
+  #dispatchChanges() {
+    this.#dispatchChangesTask?.disarm();
+    for (let [eventType, changedWindowIds] of Object.entries(
+      this.#changedWindowsByType
+    )) {
+      if (this.haveListenersForEvent(eventType) && changedWindowIds.size) {
+        this.dispatchEvent(
+          new CustomEvent(eventType, {
+            detail: {
+              windowIds: [...changedWindowIds],
+            },
+          })
+        );
+        changedWindowIds.clear();
+      }
+    }
+  }
+
+  /*
+   * @param {Window} win
+   * @returns {Array<Tab>}
+   *    The list of visible tabs for the browser window
+   */
+  getTabsForWindow(win) {
+    if (this.currentWindows.includes(win)) {
+      return [...win.gBrowser.visibleTabs];
+    }
+    return [];
+  }
+
+  /*
+   * @returns {Array<Tab>}
+   *    A by-recency-sorted, aggregated list of tabs from all the same-privateness browser windows.
+   */
+  getRecentTabs() {
+    const tabs = [];
+    for (let win of this.currentWindows) {
+      tabs.push(...this.getTabsForWindow(win));
+    }
+    tabs.sort(lastSeenActiveSort);
+    return tabs;
+  }
+
+  handleEvent({ detail, target, type }) {
+    const win = target.ownerGlobal;
+    // NOTE: we already filtered on privateness by not listening for those events
+    // from private/not-private windows
+    if (
+      type == "TabAttrModified" &&
+      !detail.changed.some(attr => TAB_ATTRS_TO_WATCH.includes(attr))
+    ) {
+      return;
+    }
+
+    if (TAB_RECENCY_CHANGE_EVENTS.includes(type)) {
+      this.#scheduleEventDispatch("TabRecencyChange", {
+        sourceWindowId: win.windowGlobalChild.innerWindowId,
+      });
+    }
+    if (TAB_CHANGE_EVENTS.includes(type)) {
+      this.#scheduleEventDispatch("TabChange", {
+        sourceWindowId: win.windowGlobalChild.innerWindowId,
+      });
+    }
+  }
+}
+
+const gExclusiveWindows = new (class {
+  perWindowInstances = new WeakMap();
+  constructor() {
+    Services.obs.addObserver(this, "domwindowclosed");
+  }
+  observe(subject, topic, data) {
+    let win = subject;
+    let winTarget = this.perWindowInstances.get(win);
+    if (winTarget) {
+      winTarget.stop();
+      this.perWindowInstances.delete(win);
+    }
+  }
+})();
+
+/**
+ * Get an OpenTabsTarget instance constrained to a specific window.
+ *
+ * @param {Window} exclusiveWindow
+ * @returns {OpenTabsTarget}
+ */
+const getTabsTargetForWindow = function (exclusiveWindow) {
+  let instance = gExclusiveWindows.perWindowInstances.get(exclusiveWindow);
+  if (instance) {
+    return instance;
+  }
+  instance = new OpenTabsTarget({
+    exclusiveWindow,
+  });
+  gExclusiveWindows.perWindowInstances.set(exclusiveWindow, instance);
+  return instance;
+};
+
+const NonPrivateTabs = new OpenTabsTarget({
+  usePrivateWindows: false,
+});
+
+const PrivateTabs = new OpenTabsTarget({
+  usePrivateWindows: true,
+});
+
+export { NonPrivateTabs, PrivateTabs, getTabsTargetForWindow };

browser/components/firefoxview/fxview-search-textbox.mjs

@@ -28,12 +28,15 @@ const SEARCH_DEBOUNCE_TIMEOUT_MS = 1000;
  *   The query that is currently in the search box.
  * @property {number} size
  *   The width (number of characters) of the search box.
+ * @property {string} pageName
+ *   The hash for the page name that the search input is located on.
  */
 export default class FxviewSearchTextbox extends MozLitElement {
   static properties = {
     placeholder: { type: String },
     query: { type: String },
     size: { type: Number },
+    pageName: { type: String },
   };
 
   static queries = {
@@ -98,6 +101,16 @@ export default class FxviewSearchTextbox extends MozLitElement {
         detail: { query: this.query },
       })
     );
+
+    Services.telemetry.recordEvent(
+      "firefoxview_next",
+      "search_initiated",
+      "search",
+      null,
+      {
+        page: this.pageName,
+      }
+    );
   }
 
   render() {

browser/components/firefoxview/history.mjs

@@ -55,6 +55,7 @@ class HistoryInView extends ViewPage {
     this.sortOption = "date";
     this.profileAge = 8;
     this.fullyUpdated = false;
+    this.cumulativeSearches = 0;
   }
 
   start() {
@@ -253,6 +254,14 @@ class HistoryInView extends ViewPage {
       {}
     );
 
+    if (this.searchQuery) {
+      const searchesHistogram = Services.telemetry.getKeyedHistogramById(
+        "FIREFOX_VIEW_CUMULATIVE_SEARCHES"
+      );
+      searchesHistogram.add("history", this.cumulativeSearches);
+      this.cumulativeSearches = 0;
+    }
+
     let currentWindow = this.getWindow();
     if (currentWindow.openTrustedLinkIn) {
       let where = lazy.BrowserUtils.whereToOpenLink(
@@ -286,6 +295,7 @@ class HistoryInView extends ViewPage {
       null,
       {
         sort_type: this.sortOption,
+        search_start: this.searchQuery ? "true" : "false",
       }
     );
     await this.updateHistoryData();
@@ -552,6 +562,7 @@ class HistoryInView extends ViewPage {
                 data-l10n-id="firefoxview-search-text-box-history"
                 data-l10n-attrs="placeholder"
                 .size=${this.searchTextboxSize}
+                pageName=${this.recentBrowsing ? "recentbrowsing" : "history"}
                 @fxview-search-textbox-query=${this.onSearchQuery}
               ></fxview-search-textbox>
             </div>`
@@ -641,6 +652,11 @@ class HistoryInView extends ViewPage {
       // from the API.
       this.createHistoryMaps();
     }
+    if (changedProperties.has("searchQuery")) {
+      this.cumulativeSearches = this.searchQuery
+        ? this.cumulativeSearches + 1
+        : 0;
+    }
   }
 }
 customElements.define("view-history", HistoryInView);

browser/components/firefoxview/opentabs.mjs

@@ -21,7 +21,8 @@ import { ViewPage, ViewPageContent } from "./viewpage.mjs";
 const lazy = {};
 
 ChromeUtils.defineESModuleGetters(lazy, {
-  EveryWindow: "resource:///modules/EveryWindow.sys.mjs",
+  NonPrivateTabs: "resource:///modules/OpenTabs.sys.mjs",
+  getTabsTargetForWindow: "resource:///modules/OpenTabs.sys.mjs",
   PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.sys.mjs",
 });
 
@@ -31,18 +32,16 @@ ChromeUtils.defineLazyGetter(lazy, "fxAccounts", () => {
   ).getFxAccountsSingleton();
 });
 
-const TOPIC_CURRENT_BROWSER_CHANGED = "net:current-browser-id";
-
 /**
  * A collection of open tabs grouped by window.
  *
- * @property {Map<Window, MozTabbrowserTab[]>} windows
- *   A mapping of windows to their respective list of open tabs.
+ * @property {Array<Window>} windows
+ *   A list of windows with the same privateness
  */
 class OpenTabsInView extends ViewPage {
   static properties = {
     ...ViewPage.properties,
-    windows: { type: Map },
+    windows: { type: Array },
     searchQuery: { type: String },
   };
   static queries = {
@@ -50,18 +49,20 @@ class OpenTabsInView extends ViewPage {
     searchTextbox: "fxview-search-textbox",
   };
 
-  static TAB_ATTRS_TO_WATCH = Object.freeze(["image", "label"]);
+  initialWindowsReady = false;
+  currentWindow = null;
+  openTabsTarget = null;
 
   constructor() {
     super();
     this._started = false;
-    this.everyWindowCallbackId = `firefoxview-${Services.uuid.generateUUID()}`;
-    this.windows = new Map();
+    this.windows = [];
     this.currentWindow = this.getWindow();
-    this.isPrivateWindow = lazy.PrivateBrowsingUtils.isWindowPrivate(
-      this.currentWindow
-    );
-    this.boundObserve = (...args) => this.observe(...args);
+    if (lazy.PrivateBrowsingUtils.isWindowPrivate(this.currentWindow)) {
+      this.openTabsTarget = lazy.getTabsTargetForWindow(this.currentWindow);
+    } else {
+      this.openTabsTarget = lazy.NonPrivateTabs;
+    }
     this.searchQuery = "";
   }
 
@@ -71,43 +72,19 @@ class OpenTabsInView extends ViewPage {
     }
     this._started = true;
 
-    Services.obs.addObserver(this.boundObserve, TOPIC_CURRENT_BROWSER_CHANGED);
+    if (this.recentBrowsing) {
+      this.openTabsTarget.addEventListener("TabRecencyChange", this);
+    } else {
+      this.openTabsTarget.addEventListener("TabChange", this);
+    }
 
-    lazy.EveryWindow.registerCallback(
-      this.everyWindowCallbackId,
-      win => {
-        if (win.gBrowser && this._shouldShowOpenTabs(win) && !win.closed) {
-          const { tabContainer } = win.gBrowser;
-          tabContainer.addEventListener("TabSelect", this);
-          tabContainer.addEventListener("TabAttrModified", this);
-          tabContainer.addEventListener("TabClose", this);
-          tabContainer.addEventListener("TabMove", this);
-          tabContainer.addEventListener("TabOpen", this);
-          tabContainer.addEventListener("TabPinned", this);
-          tabContainer.addEventListener("TabUnpinned", this);
-          // BrowserWindowWatcher doesnt always notify "net:current-browser-id" when
-          // restoring a window, so we need to listen for "activate" events here as well.
-          win.addEventListener("activate", this);
-          this._updateOpenTabsList();
-        }
-      },
-      win => {
-        if (win.gBrowser && this._shouldShowOpenTabs(win)) {
-          const { tabContainer } = win.gBrowser;
-          tabContainer.removeEventListener("TabSelect", this);
-          tabContainer.removeEventListener("TabAttrModified", this);
-          tabContainer.removeEventListener("TabClose", this);
-          tabContainer.removeEventListener("TabMove", this);
-          tabContainer.removeEventListener("TabOpen", this);
-          tabContainer.removeEventListener("TabPinned", this);
-          tabContainer.removeEventListener("TabUnpinned", this);
-          win.removeEventListener("activate", this);
-          this._updateOpenTabsList();
-        }
-      }
-    );
-    // EveryWindow will invoke the callback for existing windows - including this one
-    // So this._updateOpenTabsList will get called for the already-open window
+    // To resolve the race between this component wanting to render all the windows'
+    // tabs, while those windows are still potentially opening, flip this property
+    // once the promise resolves and we'll bail out of rendering until then.
+    this.openTabsTarget.readyWindowsPromise.finally(() => {
+      this.initialWindowsReady = true;
+      this._updateWindowList();
+    });
 
     for (let card of this.viewCards) {
       card.paused = false;
@@ -122,6 +99,13 @@ class OpenTabsInView extends ViewPage {
     }
   }
 
+  shouldUpdate(changedProperties) {
+    if (!this.initialWindowsReady) {
+      return false;
+    }
+    return super.shouldUpdate(changedProperties);
+  }
+
   disconnectedCallback() {
     super.disconnectedCallback();
     this.stop();
@@ -134,12 +118,8 @@ class OpenTabsInView extends ViewPage {
     this._started = false;
     this.paused = true;
 
-    lazy.EveryWindow.unregisterCallback(this.everyWindowCallbackId);
-
-    Services.obs.removeObserver(
-      this.boundObserve,
-      TOPIC_CURRENT_BROWSER_CHANGED
-    );
+    this.openTabsTarget.removeEventListener("TabChange", this);
+    this.openTabsTarget.removeEventListener("TabRecencyChange", this);
 
     for (let card of this.viewCards) {
       card.paused = true;
@@ -162,14 +142,6 @@ class OpenTabsInView extends ViewPage {
     this.stop();
   }
 
-  async observe(subject, topic, data) {
-    switch (topic) {
-      case TOPIC_CURRENT_BROWSER_CHANGED:
-        this.requestUpdate();
-        break;
-    }
-  }
-
   render() {
     if (this.recentBrowsing) {
       return this.getRecentBrowsingTemplate();
@@ -177,7 +149,8 @@ class OpenTabsInView extends ViewPage {
     let currentWindowIndex, currentWindowTabs;
     let index = 1;
     const otherWindows = [];
-    this.windows.forEach((tabs, win) => {
+    this.windows.forEach(win => {
+      const tabs = this.openTabsTarget.getTabsForWindow(win);
       if (win === this.currentWindow) {
         currentWindowIndex = index++;
         currentWindowTabs = tabs;
@@ -187,13 +160,13 @@ class OpenTabsInView extends ViewPage {
     });
 
     const cardClasses = classMap({
-      "height-limited": this.windows.size > 3,
-      "width-limited": this.windows.size > 1,
+      "height-limited": this.windows.length > 3,
+      "width-limited": this.windows.length > 1,
     });
     let cardCount;
-    if (this.windows.size <= 1) {
+    if (this.windows.length <= 1) {
       cardCount = "one";
-    } else if (this.windows.size === 2) {
+    } else if (this.windows.length === 2) {
       cardCount = "two";
     } else {
       cardCount = "three-or-more";
@@ -220,6 +193,7 @@ class OpenTabsInView extends ViewPage {
               data-l10n-attrs="placeholder"
               @fxview-search-textbox-query=${this.onSearchQuery}
               .size=${this.searchTextboxSize}
+              pageName=${this.recentBrowsing ? "recentbrowsing" : "opentabs"}
             ></fxview-search-textbox>
           </div>`
         )}
@@ -276,19 +250,7 @@ class OpenTabsInView extends ViewPage {
    *   The recent browsing template.
    */
   getRecentBrowsingTemplate() {
-    const tabs = Array.from(this.windows.values())
-      .flat()
-      .sort((a, b) => {
-        let dt = b.lastSeenActive - a.lastSeenActive;
-        if (dt) {
-          return dt;
-        }
-        // try to break a deadlock by sorting the selected tab higher
-        if (!(a.selected || b.selected)) {
-          return 0;
-        }
-        return a.selected ? -1 : 1;
-      });
+    const tabs = this.openTabsTarget.getRecentTabs();
     return html`<view-opentabs-card
       .tabs=${tabs}
       .recentBrowsing=${true}
@@ -302,76 +264,46 @@ class OpenTabsInView extends ViewPage {
       this.onSearchQuery({ detail });
       return;
     }
-    const win = target.ownerGlobal;
-    const tabs = this.windows.get(win);
+    let windowIds;
     switch (type) {
-      case "TabSelect": {
+      case "TabRecencyChange":
+      case "TabChange":
         // if we're switching away from our tab, we can halt any updates immediately
-        if (detail.previousTab == this.getBrowserTab()) {
+        if (!this.isSelectedBrowserTab) {
           this.stop();
-        }
-        return;
-      }
-      case "TabAttrModified":
-        if (
-          !detail.changed.some(attr =>
-            OpenTabsInView.TAB_ATTRS_TO_WATCH.includes(attr)
-          )
-        ) {
-          // We don't care about this attr, bail out to avoid change detection.
           return;
         }
-        break;
-      case "TabClose":
-        tabs.splice(target._tPos, 1);
-        break;
-      case "TabMove":
-        [tabs[detail], tabs[target._tPos]] = [tabs[target._tPos], tabs[detail]];
-        break;
-      case "TabOpen":
-        tabs.splice(target._tPos, 0, target);
-        break;
-      case "TabPinned":
-      case "TabUnpinned":
-        this.windows.set(win, [...win.gBrowser.tabs]);
+        windowIds = detail.windowIds;
+        this._updateWindowList();
         break;
     }
-    this.requestUpdate();
-    if (!this.recentBrowsing) {
-      const cardForWin = this.shadowRoot.querySelector(
-        `view-opentabs-card[data-inner-id="${win.windowGlobalChild.innerWindowId}"]`
+    if (this.recentBrowsing) {
+      return;
+    }
+    if (windowIds?.length) {
+      // there were tab changes to one or more windows
+      for (let winId of windowIds) {
+        const cardForWin = this.shadowRoot.querySelector(
+          `view-opentabs-card[data-inner-id="${winId}"]`
+        );
+        if (this.searchQuery) {
+          cardForWin?.updateSearchResults();
+        }
+        cardForWin?.requestUpdate();
+      }
+    } else {
+      let winId = window.windowGlobalChild.innerWindowId;
+      let cardForWin = this.shadowRoot.querySelector(
+        `view-opentabs-card[data-inner-id="${winId}"]`
       );
       if (this.searchQuery) {
         cardForWin?.updateSearchResults();
       }
-      cardForWin?.requestUpdate();
     }
   }
 
-  _updateOpenTabsList() {
-    this.windows = this._getOpenTabsPerWindow();
-  }
-
-  /**
-   * Get a list of open tabs for each window.
-   *
-   * @returns {Map<Window, MozTabbrowserTab[]>}
-   */
-  _getOpenTabsPerWindow() {
-    return new Map(
-      Array.from(Services.wm.getEnumerator("navigator:browser"))
-        .filter(
-          win => win.gBrowser && this._shouldShowOpenTabs(win) && !win.closed
-        )
-        .map(win => [win, [...win.gBrowser.tabs]])
-    );
-  }
-
-  _shouldShowOpenTabs(win) {
-    return (
-      win == this.currentWindow ||
-      (!this.isPrivateWindow && !lazy.PrivateBrowsingUtils.isWindowPrivate(win))
-    );
+  async _updateWindowList() {
+    this.windows = this.openTabsTarget.currentWindows;
   }
 }
 customElements.define("view-opentabs", OpenTabsInView);
@@ -395,6 +327,7 @@ class OpenTabsInViewCard extends ViewPageContent {
     searchQuery: { type: String },
     searchResults: { type: Array },
     showAll: { type: Boolean },
+    cumulativeSearches: { type: Number },
   };
   static MAX_TABS_FOR_COMPACT_HEIGHT = 7;
 
@@ -408,6 +341,7 @@ class OpenTabsInViewCard extends ViewPageContent {
     this.searchQuery = "";
     this.searchResults = null;
     this.showAll = false;
+    this.cumulativeSearches = 0;
   }
 
   static queries = {
@@ -460,6 +394,15 @@ class OpenTabsInViewCard extends ViewPageContent {
       (event.type == "keydown" && event.code == "Space")
     ) {
       event.preventDefault();
+      Services.telemetry.recordEvent(
+        "firefoxview_next",
+        "search_show_all",
+        "showallbutton",
+        null,
+        {
+          section: "opentabs",
+        }
+      );
       this.showAll = true;
     }
   }
@@ -480,6 +423,16 @@ class OpenTabsInViewCard extends ViewPageContent {
         window: this.title || "Window 1 (Current)",
       }
     );
+    if (this.searchQuery) {
+      const searchesHistogram = Services.telemetry.getKeyedHistogramById(
+        "FIREFOX_VIEW_CUMULATIVE_SEARCHES"
+      );
+      searchesHistogram.add(
+        this.recentBrowsing ? "recentbrowsing" : "opentabs",
+        this.cumulativeSearches
+      );
+      this.cumulativeSearches = 0;
+    }
   }
 
   viewVisibleCallback() {
@@ -559,6 +512,9 @@ class OpenTabsInViewCard extends ViewPageContent {
   willUpdate(changedProperties) {
     if (changedProperties.has("searchQuery")) {
       this.showAll = false;
+      this.cumulativeSearches = this.searchQuery
+        ? this.cumulativeSearches + 1
+        : 0;
     }
     if (changedProperties.has("searchQuery") || changedProperties.has("tabs")) {
       this.updateSearchResults();

browser/components/firefoxview/recentbrowsing.mjs

@@ -54,6 +54,7 @@ class RecentBrowsingInView extends ViewPage {
               data-l10n-id="firefoxview-search-text-box-recentbrowsing"
               data-l10n-attrs="placeholder"
               .size=${this.searchTextboxSize}
+              pageName="recentbrowsing"
             ></fxview-search-textbox>
           </div>`
         )}

browser/components/firefoxview/recentlyclosed.mjs

@@ -48,12 +48,14 @@ class RecentlyClosedTabsInView extends ViewPage {
     this.searchQuery = "";
     this.searchResults = null;
     this.showAll = false;
+    this.cumulativeSearches = 0;
   }
 
   static properties = {
     ...ViewPage.properties,
     searchResults: { type: Array },
     showAll: { type: Boolean },
+    cumulativeSearches: { type: Number },
   };
 
   static queries = {
@@ -232,6 +234,16 @@ class RecentlyClosedTabsInView extends ViewPage {
         page: this.recentBrowsing ? "recentbrowsing" : "recentlyclosed",
       }
     );
+    if (this.searchQuery) {
+      const searchesHistogram = Services.telemetry.getKeyedHistogramById(
+        "FIREFOX_VIEW_CUMULATIVE_SEARCHES"
+      );
+      searchesHistogram.add(
+        this.recentBrowsing ? "recentbrowsing" : "recentlyclosed",
+        this.cumulativeSearches
+      );
+      this.cumulativeSearches = 0;
+    }
   }
 
   onDismissTab(e) {
@@ -267,8 +279,13 @@ class RecentlyClosedTabsInView extends ViewPage {
     );
   }
 
-  willUpdate() {
+  willUpdate(changedProperties) {
     this.fullyUpdated = false;
+    if (changedProperties.has("searchQuery")) {
+      this.cumulativeSearches = this.searchQuery
+        ? this.cumulativeSearches + 1
+        : 0;
+    }
   }
 
   updated() {
@@ -350,6 +367,9 @@ class RecentlyClosedTabsInView extends ViewPage {
                 data-l10n-attrs="placeholder"
                 @fxview-search-textbox-query=${this.onSearchQuery}
                 .size=${this.searchTextboxSize}
+                pageName=${this.recentBrowsing
+                  ? "recentbrowsing"
+                  : "recentlyclosed"}
               ></fxview-search-textbox>
             </div>`
           )}
@@ -441,6 +461,15 @@ class RecentlyClosedTabsInView extends ViewPage {
     ) {
       event.preventDefault();
       this.showAll = true;
+      Services.telemetry.recordEvent(
+        "firefoxview_next",
+        "search_show_all",
+        "showallbutton",
+        null,
+        {
+          section: "recentlyclosed",
+        }
+      );
     }
   }
 }

browser/components/firefoxview/syncedtabs.mjs

@@ -51,6 +51,7 @@ class SyncedTabsInView extends ViewPage {
     this.fullyUpdated = false;
     this.searchQuery = "";
     this.showAll = false;
+    this.cumulativeSearches = 0;
   }
 
   static properties = {
@@ -61,6 +62,7 @@ class SyncedTabsInView extends ViewPage {
     devices: { type: Array },
     searchQuery: { type: String },
     showAll: { type: Boolean },
+    cumulativeSearches: { type: Number },
   };
 
   static queries = {
@@ -113,6 +115,14 @@ class SyncedTabsInView extends ViewPage {
     }
   }
 
+  willUpdate(changedProperties) {
+    if (changedProperties.has("searchQuery")) {
+      this.cumulativeSearches = this.searchQuery
+        ? this.cumulativeSearches + 1
+        : 0;
+    }
+  }
+
   disconnectedCallback() {
     super.disconnectedCallback();
     this.stop();
@@ -318,6 +328,16 @@ class SyncedTabsInView extends ViewPage {
         }
       );
     }
+    if (this.searchQuery) {
+      const searchesHistogram = Services.telemetry.getKeyedHistogramById(
+        "FIREFOX_VIEW_CUMULATIVE_SEARCHES"
+      );
+      searchesHistogram.add(
+        this.recentBrowsing ? "recentbrowsing" : "syncedtabs",
+        this.cumulativeSearches
+      );
+      this.cumulativeSearches = 0;
+    }
   }
 
   onContextMenu(e) {
@@ -502,6 +522,15 @@ class SyncedTabsInView extends ViewPage {
     ) {
       event.preventDefault();
       this.showAll = true;
+      Services.telemetry.recordEvent(
+        "firefoxview_next",
+        "search_show_all",
+        "showallbutton",
+        null,
+        {
+          section: "syncedtabs",
+        }
+      );
     }
   }
 
@@ -569,6 +598,9 @@ class SyncedTabsInView extends ViewPage {
                   data-l10n-attrs="placeholder"
                   @fxview-search-textbox-query=${this.onSearchQuery}
                   .size=${this.searchTextboxSize}
+                  pageName=${this.recentBrowsing
+                    ? "recentbrowsing"
+                    : "syncedtabs"}
                 ></fxview-search-textbox>
               </div>`
             )}

browser/components/firefoxview/tests/browser/browser.toml

@@ -32,6 +32,8 @@ skip-if = ["true"] # Bug 1869605 and # Bug 1870296
 ["browser_notification_dot.js"]
 skip-if = ["true"] # Bug 1851453
 
+["browser_opentabs_changes.js"]
+
 ["browser_reload_firefoxview.js"]
 
 ["browser_tab_close_last_tab.js"]

browser/components/firefoxview/tests/browser/browser_firefoxview_paused.js

@@ -5,6 +5,9 @@ const tabURL1 = "data:,Tab1";
 const tabURL2 = "data:,Tab2";
 const tabURL3 = "data:,Tab3";
 
+const { NonPrivateTabs } = ChromeUtils.importESModule(
+  "resource:///modules/OpenTabs.sys.mjs"
+);
 const TestTabs = {};
 
 function getTopLevelViewElements(document) {
@@ -38,6 +41,8 @@ async function getElements(document) {
     await TestUtils.waitForCondition(() => recentlyClosedView.fullyUpdated);
   }
   let recentlyClosedList = recentlyClosedView.tabList;
+  await openTabsView.openTabsTarget.readyWindowsPromise;
+  await openTabsView.updateComplete;
   let openTabsList =
     openTabsView.shadowRoot.querySelector("view-opentabs-card")?.tabList;
 
@@ -84,6 +89,17 @@ async function setupOpenAndClosedTabs() {
   await SessionStoreTestUtils.closeTab(TestTabs.tab3);
 }
 
+function assertSpiesCalled(spiesMap, expectCalled) {
+  let message = expectCalled ? "to be called" : "to not be called";
+  for (let [elem, renderSpy] of spiesMap.entries()) {
+    is(
+      expectCalled,
+      renderSpy.called,
+      `Expected the render method spy on element ${elem.localName} ${message}`
+    );
+  }
+}
+
 async function checkFxRenderCalls(browser, elements, selectedView) {
   const sandbox = sinon.createSandbox();
   const topLevelViews = getTopLevelViewElements(browser.contentDocument);
@@ -119,7 +135,20 @@ async function checkFxRenderCalls(browser, elements, selectedView) {
   }
 
   info("test switches to tab2");
+  let tabChangeRaised = BrowserTestUtils.waitForEvent(
+    NonPrivateTabs,
+    "TabRecencyChange"
+  );
   await BrowserTestUtils.switchTab(gBrowser, TestTabs.tab2);
+  await tabChangeRaised;
+  info(
+    "TabRecencyChange event was raised, check no render() methods were called"
+  );
+  assertSpiesCalled(viewSpies, false);
+  assertSpiesCalled(elementSpies, false);
+  for (let renderSpy of [...viewSpies.values(), ...elementSpies.values()]) {
+    renderSpy.resetHistory();
+  }
 
   // check all the top-level views are paused
   ok(
@@ -132,21 +161,14 @@ async function checkFxRenderCalls(browser, elements, selectedView) {
   );
   ok(topLevelViews.openTabsView.paused, "The open tabs view is paused");
 
-  function assertSpiesCalled(spiesMap, expectCalled) {
-    let message = expectCalled ? "to be called" : "to not be called";
-    for (let [elem, renderSpy] of spiesMap.entries()) {
-      is(
-        expectCalled,
-        renderSpy.called,
-        `Expected the render method spy on element ${elem.localName} ${message}`
-      );
-    }
-  }
-
   await nextFrame();
   info("test removes tab1");
+  tabChangeRaised = BrowserTestUtils.waitForEvent(
+    NonPrivateTabs,
+    "TabRecencyChange"
+  );
   await BrowserTestUtils.removeTab(TestTabs.tab1);
-  await nextFrame();
+  await tabChangeRaised;
 
   assertSpiesCalled(viewSpies, false);
   assertSpiesCalled(elementSpies, false);

browser/components/firefoxview/tests/browser/browser_history_firefoxview.js

@@ -210,7 +210,7 @@ add_task(async function test_list_ordering() {
         "sort_history",
         "tabs",
         undefined,
-        { sort_type: "site" },
+        { sort_type: "site", search_start: "false" },
       ],
     ];
     // Select sort by site option
@@ -238,7 +238,7 @@ add_task(async function test_list_ordering() {
         "sort_history",
         "tabs",
         undefined,
-        { sort_type: "date" },
+        { sort_type: "date", search_start: "false" },
       ],
     ];
     // Select sort by date option

browser/components/firefoxview/tests/browser/browser_opentabs_cards.js

@@ -7,6 +7,9 @@ const ROW_DATE_ID = "fxview-tab-row-date";
 
 let gInitialTab;
 let gInitialTabURL;
+const { NonPrivateTabs } = ChromeUtils.importESModule(
+  "resource:///modules/OpenTabs.sys.mjs"
+);
 
 add_setup(function () {
   // This test opens a lot of windows and tabs and might run long on slower configurations
@@ -65,7 +68,8 @@ add_task(async function open_tab_same_window() {
     const browser = viewTab.linkedBrowser;
     await navigateToOpenTabs(browser);
     const openTabs = getOpenTabsComponent(browser);
-    await openTabs.getUpdateComplete();
+    await openTabs.openTabsTarget.readyWindowsPromise;
+    await openTabs.updateComplete;
 
     const cards = getCards(browser);
     is(cards.length, 1, "There is one window.");
@@ -80,15 +84,23 @@ add_task(async function open_tab_same_window() {
       browser.contentDocument,
       "visibilitychange"
     );
+    let tabChangeRaised = BrowserTestUtils.waitForEvent(
+      NonPrivateTabs,
+      "TabChange"
+    );
     await BrowserTestUtils.openNewForegroundTab(gBrowser, TEST_URL);
     await promiseHidden;
+    await tabChangeRaised;
   });
 
   const [originalTab, newTab] = gBrowser.visibleTabs;
 
   await openFirefoxViewTab(window).then(async viewTab => {
     const browser = viewTab.linkedBrowser;
-    await TestUtils.waitForTick();
+    const openTabs = getOpenTabsComponent(browser);
+    await openTabs.openTabsTarget.readyWindowsPromise;
+    await openTabs.updateComplete;
+
     const cards = getCards(browser);
     is(cards.length, 1, "There is one window.");
     let tabItems = await getRowsForCard(cards[0]);
@@ -131,10 +143,15 @@ add_task(async function open_tab_same_window() {
     const browser = viewTab.linkedBrowser;
     const cards = getCards(browser);
     let tabItems;
+    let tabChangeRaised = BrowserTestUtils.waitForEvent(
+      NonPrivateTabs,
+      "TabChange"
+    );
 
     info("Bring the new tab to the front.");
     gBrowser.moveTabTo(newTab, 0);
 
+    await tabChangeRaised;
     await BrowserTestUtils.waitForMutationCondition(
       cards[0].shadowRoot,
       { childList: true, subtree: true },
@@ -143,7 +160,12 @@ add_task(async function open_tab_same_window() {
         return tabItems[0].url === TEST_URL;
       }
     );
+    tabChangeRaised = BrowserTestUtils.waitForEvent(
+      NonPrivateTabs,
+      "TabChange"
+    );
     await BrowserTestUtils.removeTab(newTab);
+    await tabChangeRaised;
 
     const [card] = getCards(browser);
     await TestUtils.waitForCondition(
@@ -174,7 +196,8 @@ add_task(async function open_tab_new_window() {
     const browser = viewTab.linkedBrowser;
     await navigateToOpenTabs(browser);
     const openTabs = getOpenTabsComponent(browser);
-    await openTabs.getUpdateComplete();
+    await openTabs.openTabsTarget.readyWindowsPromise;
+    await openTabs.updateComplete;
 
     const cards = getCards(browser);
     is(cards.length, 2, "There are two windows.");
@@ -197,8 +220,13 @@ add_task(async function open_tab_new_window() {
       "The date is hidden, since we have two windows."
     );
     info("Select a tab from the original window.");
+    let tabChangeRaised = BrowserTestUtils.waitForEvent(
+      NonPrivateTabs,
+      "TabRecencyChange"
+    );
     winFocused = BrowserTestUtils.waitForEvent(window, "focus", true);
     originalWinRows[0].mainEl.click();
+    await tabChangeRaised;
   });
 
   info("Wait for the original window to be focused");
@@ -208,7 +236,8 @@ add_task(async function open_tab_new_window() {
     const browser = viewTab.linkedBrowser;
     await navigateToOpenTabs(browser);
     const openTabs = getOpenTabsComponent(browser);
-    await openTabs.getUpdateComplete();
+    await openTabs.openTabsTarget.readyWindowsPromise;
+    await openTabs.updateComplete;
 
     const cards = getCards(browser);
     is(cards.length, 2, "There are two windows.");
@@ -216,7 +245,12 @@ add_task(async function open_tab_new_window() {
 
     info("Select a tab from the new window.");
     winFocused = BrowserTestUtils.waitForEvent(win, "focus", true);
+    let tabChangeRaised = BrowserTestUtils.waitForEvent(
+      NonPrivateTabs,
+      "TabRecencyChange"
+    );
     newWinRows[0].mainEl.click();
+    await tabChangeRaised;
   });
   info("Wait for the new window to be focused");
   await winFocused;
@@ -231,7 +265,8 @@ add_task(async function open_tab_new_private_window() {
     const browser = viewTab.linkedBrowser;
     await navigateToOpenTabs(browser);
     const openTabs = getOpenTabsComponent(browser);
-    await openTabs.getUpdateComplete();
+    await openTabs.openTabsTarget.readyWindowsPromise;
+    await openTabs.updateComplete;
 
     const cards = getCards(browser);
     is(cards.length, 1, "The private window is not displayed.");
@@ -244,33 +279,61 @@ add_task(async function styling_for_multiple_windows() {
     const browser = viewTab.linkedBrowser;
     await navigateToOpenTabs(browser);
     const openTabs = getOpenTabsComponent(browser);
-    await openTabs.getUpdateComplete();
+    await openTabs.openTabsTarget.readyWindowsPromise;
+    await openTabs.updateComplete;
 
     ok(
       openTabs.shadowRoot.querySelector("[card-count=one]"),
       "The container shows one column when one window is open."
     );
   });
+
   await BrowserTestUtils.openNewBrowserWindow();
+  let tabChangeRaised = BrowserTestUtils.waitForEvent(
+    NonPrivateTabs,
+    "TabChange"
+  );
+  await NonPrivateTabs.readyWindowsPromise;
+  await tabChangeRaised;
+  is(
+    NonPrivateTabs.currentWindows.length,
+    2,
+    "NonPrivateTabs now has 2 currentWindows"
+  );
 
   info("switch to firefox view in the first window");
   SimpleTest.promiseFocus(window);
   await openFirefoxViewTab(window).then(async viewTab => {
     const browser = viewTab.linkedBrowser;
     const openTabs = getOpenTabsComponent(browser);
-    await openTabs.getUpdateComplete();
+    await openTabs.openTabsTarget.readyWindowsPromise;
+    await openTabs.updateComplete;
+    is(
+      openTabs.openTabsTarget.currentWindows.length,
+      2,
+      "There should be 2 current windows"
+    );
     ok(
       openTabs.shadowRoot.querySelector("[card-count=two]"),
       "The container shows two columns when two windows are open."
     );
   });
   await BrowserTestUtils.openNewBrowserWindow();
+  tabChangeRaised = BrowserTestUtils.waitForEvent(NonPrivateTabs, "TabChange");
+  await NonPrivateTabs.readyWindowsPromise;
+  await tabChangeRaised;
+  is(
+    NonPrivateTabs.currentWindows.length,
+    3,
+    "NonPrivateTabs now has 2 currentWindows"
+  );
 
   SimpleTest.promiseFocus(window);
   await openFirefoxViewTab(window).then(async viewTab => {
     const browser = viewTab.linkedBrowser;
     const openTabs = getOpenTabsComponent(browser);
-    await openTabs.getUpdateComplete();
+    await openTabs.openTabsTarget.readyWindowsPromise;
+    await openTabs.updateComplete;
 
     ok(
       openTabs.shadowRoot.querySelector("[card-count=three-or-more]"),
@@ -306,7 +369,8 @@ add_task(async function toggle_show_more_link() {
     const browser = viewTab.linkedBrowser;
     await navigateToOpenTabs(browser);
     const openTabs = getOpenTabsComponent(browser);
-    await openTabs.getUpdateComplete();
+    await openTabs.openTabsTarget.readyWindowsPromise;
+    await openTabs.updateComplete;
 
     const cards = getCards(browser);
     is(cards.length, NUMBER_OF_WINDOWS, "There are four windows.");
@@ -321,7 +385,8 @@ add_task(async function toggle_show_more_link() {
   await openFirefoxViewTab(window).then(async viewTab => {
     const browser = viewTab.linkedBrowser;
     const openTabs = getOpenTabsComponent(browser);
-    await openTabs.getUpdateComplete();
+    await openTabs.openTabsTarget.readyWindowsPromise;
+    await openTabs.updateComplete;
     Assert.less(
       (await getRowsForCard(lastCard)).length,
       NUMBER_OF_TABS,
@@ -392,7 +457,8 @@ add_task(async function search_open_tabs() {
     const browser = viewTab.linkedBrowser;
     await navigateToOpenTabs(browser);
     const openTabs = getOpenTabsComponent(browser);
-    await openTabs.getUpdateComplete();
+    await openTabs.openTabsTarget.readyWindowsPromise;
+    await openTabs.updateComplete;
 
     const cards = getCards(browser);
     is(cards.length, 2, "There are two windows.");

browser/components/firefoxview/tests/browser/browser_opentabs_changes.js

@@ -0,0 +1,541 @@
+const { NonPrivateTabs, getTabsTargetForWindow } = ChromeUtils.importESModule(
+  "resource:///modules/OpenTabs.sys.mjs"
+);
+let privateTabsChanges;
+
+const tabURL1 = "data:text/html,<title>Tab1</title>Tab1";
+const tabURL2 = "data:text/html,<title>Tab2</title>Tab2";
+const tabURL3 = "data:text/html,<title>Tab3</title>Tab3";
+const tabURL4 = "data:text/html,<title>Tab4</title>Tab4";
+
+const nonPrivateListener = sinon.stub();
+const privateListener = sinon.stub();
+
+function tabUrl(tab) {
+  return tab.linkedBrowser.currentURI?.spec;
+}
+
+function getWindowId(win) {
+  return win.windowGlobalChild.innerWindowId;
+}
+
+async function setup(tabChangeEventName) {
+  nonPrivateListener.resetHistory();
+  privateListener.resetHistory();
+
+  NonPrivateTabs.addEventListener(tabChangeEventName, nonPrivateListener);
+
+  await TestUtils.waitForTick();
+  is(
+    NonPrivateTabs.currentWindows.length,
+    1,
+    "NonPrivateTabs has 1 window a tick after adding the event listener"
+  );
+
+  info("Opening new windows");
+  let win0 = window,
+    win1 = await BrowserTestUtils.openNewBrowserWindow(),
+    privateWin = await BrowserTestUtils.openNewBrowserWindow({
+      private: true,
+    });
+  BrowserTestUtils.startLoadingURIString(
+    win1.gBrowser.selectedBrowser,
+    tabURL1
+  );
+  await BrowserTestUtils.browserLoaded(win1.gBrowser.selectedBrowser);
+
+  // load a tab with a title/label we can easily verify
+  BrowserTestUtils.startLoadingURIString(
+    privateWin.gBrowser.selectedBrowser,
+    tabURL2
+  );
+  await BrowserTestUtils.browserLoaded(privateWin.gBrowser.selectedBrowser);
+
+  is(
+    win1.gBrowser.selectedTab.label,
+    "Tab1",
+    "Check the tab label in the new non-private window"
+  );
+  is(
+    privateWin.gBrowser.selectedTab.label,
+    "Tab2",
+    "Check the tab label in the new private window"
+  );
+
+  privateTabsChanges = getTabsTargetForWindow(privateWin);
+  privateTabsChanges.addEventListener(tabChangeEventName, privateListener);
+  is(
+    privateTabsChanges,
+    getTabsTargetForWindow(privateWin),
+    "getTabsTargetForWindow reuses a single instance per exclusive window"
+  );
+
+  await TestUtils.waitForTick();
+  is(
+    NonPrivateTabs.currentWindows.length,
+    2,
+    "NonPrivateTabs has 2 windows once openNewBrowserWindow resolves"
+  );
+  is(
+    privateTabsChanges.currentWindows.length,
+    1,
+    "privateTabsChanges has 1 window once openNewBrowserWindow resolves"
+  );
+
+  await SimpleTest.promiseFocus(win0);
+  info("setup, win0 has id: " + getWindowId(win0));
+  info("setup, win1 has id: " + getWindowId(win1));
+  info("setup, privateWin has id: " + getWindowId(privateWin));
+  info("setup,waiting for both private and nonPrivateListener to be called");
+  await TestUtils.waitForCondition(() => {
+    return nonPrivateListener.called && privateListener.called;
+  });
+  nonPrivateListener.resetHistory();
+  privateListener.resetHistory();
+
+  const cleanup = async eventName => {
+    NonPrivateTabs.removeEventListener(eventName, nonPrivateListener);
+    privateTabsChanges.removeEventListener(eventName, privateListener);
+    await SimpleTest.promiseFocus(window);
+    await promiseAllButPrimaryWindowClosed();
+  };
+  return { windows: [win0, win1, privateWin], cleanup };
+}
+
+add_task(async function test_TabChanges() {
+  const { windows, cleanup } = await setup("TabChange");
+  const [win0, win1, privateWin] = windows;
+  let tabChangeRaised;
+  let changeEvent;
+
+  info(
+    "Verify that manipulating tabs in a non-private window dispatches events on the correct target"
+  );
+  for (let win of [win0, win1]) {
+    tabChangeRaised = BrowserTestUtils.waitForEvent(
+      NonPrivateTabs,
+      "TabChange"
+    );
+    let newTab = await BrowserTestUtils.openNewForegroundTab(
+      win.gBrowser,
+      tabURL1
+    );
+    changeEvent = await tabChangeRaised;
+    Assert.deepEqual(
+      changeEvent.detail.windowIds,
+      [getWindowId(win)],
+      "The event had the correct window id"
+    );
+
+    tabChangeRaised = BrowserTestUtils.waitForEvent(
+      NonPrivateTabs,
+      "TabChange"
+    );
+    const navigateUrl = "https://example.org/";
+    BrowserTestUtils.startLoadingURIString(newTab.linkedBrowser, navigateUrl);
+    await BrowserTestUtils.browserLoaded(
+      newTab.linkedBrowser,
+      null,
+      navigateUrl
+    );
+    // navigation in a tab changes the label which should produce a change event
+    changeEvent = await tabChangeRaised;
+    Assert.deepEqual(
+      changeEvent.detail.windowIds,
+      [getWindowId(win)],
+      "The event had the correct window id"
+    );
+
+    tabChangeRaised = BrowserTestUtils.waitForEvent(
+      NonPrivateTabs,
+      "TabChange"
+    );
+    BrowserTestUtils.removeTab(newTab);
+    // navigation in a tab changes the label which should produce a change event
+    changeEvent = await tabChangeRaised;
+    Assert.deepEqual(
+      changeEvent.detail.windowIds,
+      [getWindowId(win)],
+      "The event had the correct window id"
+    );
+  }
+
+  info(
+    "make sure a change to a private window doesnt dispatch on a nonprivate target"
+  );
+  nonPrivateListener.resetHistory();
+  privateListener.resetHistory();
+
+  tabChangeRaised = BrowserTestUtils.waitForEvent(
+    privateTabsChanges,
+    "TabChange"
+  );
+  BrowserTestUtils.addTab(privateWin.gBrowser, tabURL1);
+  changeEvent = await tabChangeRaised;
+  info(
+    `Check windowIds adding tab to private window: ${getWindowId(
+      privateWin
+    )}: ${JSON.stringify(changeEvent.detail.windowIds)}`
+  );
+  Assert.deepEqual(
+    changeEvent.detail.windowIds,
+    [getWindowId(privateWin)],
+    "The event had the correct window id"
+  );
+  await TestUtils.waitForTick();
+  Assert.ok(
+    nonPrivateListener.notCalled,
+    "A private tab change shouldnt raise a tab change event on the non-private target"
+  );
+
+  info("testTabChanges complete");
+  await cleanup("TabChange");
+});
+
+add_task(async function test_TabRecencyChange() {
+  const { windows, cleanup } = await setup("TabRecencyChange");
+  const [win0, win1, privateWin] = windows;
+
+  let tabChangeRaised;
+  let changeEvent;
+  let sortedTabs;
+
+  info("Open some tabs in the non-private windows");
+  for (let win of [win0, win1]) {
+    for (let url of [tabURL1, tabURL2]) {
+      let tab = BrowserTestUtils.addTab(win.gBrowser, url);
+      tabChangeRaised = BrowserTestUtils.waitForEvent(
+        NonPrivateTabs,
+        "TabChange"
+      );
+      await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+      await tabChangeRaised;
+    }
+  }
+
+  info("Verify switching tabs produces the expected event and result");
+  nonPrivateListener.resetHistory();
+  privateListener.resetHistory();
+
+  tabChangeRaised = BrowserTestUtils.waitForEvent(
+    NonPrivateTabs,
+    "TabRecencyChange"
+  );
+  BrowserTestUtils.switchTab(win0.gBrowser, win0.gBrowser.tabs.at(-1));
+  changeEvent = await tabChangeRaised;
+
+  Assert.deepEqual(
+    changeEvent.detail.windowIds,
+    [getWindowId(win0)],
+    "The recency change event had the correct window id"
+  );
+  Assert.ok(
+    nonPrivateListener.called,
+    "Sanity check that the non-private tabs listener was called"
+  );
+  Assert.ok(
+    privateListener.notCalled,
+    "The private tabs listener was not called"
+  );
+
+  sortedTabs = NonPrivateTabs.getRecentTabs();
+  is(
+    sortedTabs[0],
+    win0.gBrowser.selectedTab,
+    "The most-recent tab is the selected tab"
+  );
+
+  info("Verify switching window produces the expected event and result");
+  nonPrivateListener.resetHistory();
+  privateListener.resetHistory();
+
+  tabChangeRaised = BrowserTestUtils.waitForEvent(
+    NonPrivateTabs,
+    "TabRecencyChange"
+  );
+  await SimpleTest.promiseFocus(win1);
+  changeEvent = await tabChangeRaised;
+  Assert.deepEqual(
+    changeEvent.detail.windowIds,
+    [getWindowId(win1)],
+    "The recency change event had the correct window id"
+  );
+  Assert.ok(
+    nonPrivateListener.called,
+    "Sanity check that the non-private tabs listener was called"
+  );
+  Assert.ok(
+    privateListener.notCalled,
+    "The private tabs listener was not called"
+  );
+
+  sortedTabs = NonPrivateTabs.getRecentTabs();
+  is(
+    sortedTabs[0],
+    win1.gBrowser.selectedTab,
+    "The most-recent tab is the selected tab in the current window"
+  );
+
+  info("Verify behavior with private window changes");
+  nonPrivateListener.resetHistory();
+  privateListener.resetHistory();
+
+  tabChangeRaised = BrowserTestUtils.waitForEvent(
+    privateTabsChanges,
+    "TabRecencyChange"
+  );
+  await SimpleTest.promiseFocus(privateWin);
+  changeEvent = await tabChangeRaised;
+  Assert.deepEqual(
+    changeEvent.detail.windowIds,
+    [getWindowId(privateWin)],
+    "The recency change event had the correct window id"
+  );
+  Assert.ok(
+    nonPrivateListener.notCalled,
+    "The non-private listener got no recency-change events from the private window"
+  );
+  Assert.ok(
+    privateListener.called,
+    "Sanity check the private tabs listener was called"
+  );
+
+  sortedTabs = privateTabsChanges.getRecentTabs();
+  is(
+    sortedTabs[0],
+    privateWin.gBrowser.selectedTab,
+    "The most-recent tab is the selected tab in the current window"
+  );
+  sortedTabs = NonPrivateTabs.getRecentTabs();
+  is(
+    sortedTabs[0],
+    win1.gBrowser.selectedTab,
+    "The most-recent non-private tab is still the selected tab in the previous non-private window"
+  );
+
+  info("Verify adding a tab to a private window does the right thing");
+  nonPrivateListener.resetHistory();
+  privateListener.resetHistory();
+
+  tabChangeRaised = BrowserTestUtils.waitForEvent(
+    privateTabsChanges,
+    "TabRecencyChange"
+  );
+  await BrowserTestUtils.openNewForegroundTab(privateWin.gBrowser, tabURL3);
+  changeEvent = await tabChangeRaised;
+  Assert.deepEqual(
+    changeEvent.detail.windowIds,
+    [getWindowId(privateWin)],
+    "The event had the correct window id"
+  );
+  Assert.ok(
+    nonPrivateListener.notCalled,
+    "The non-private listener got no recency-change events from the private window"
+  );
+  sortedTabs = privateTabsChanges.getRecentTabs();
+  is(
+    tabUrl(sortedTabs[0]),
+    tabURL3,
+    "The most-recent tab is the tab we just opened in the private window"
+  );
+
+  nonPrivateListener.resetHistory();
+  privateListener.resetHistory();
+
+  tabChangeRaised = BrowserTestUtils.waitForEvent(
+    privateTabsChanges,
+    "TabRecencyChange"
+  );
+  BrowserTestUtils.switchTab(privateWin.gBrowser, privateWin.gBrowser.tabs[0]);
+  changeEvent = await tabChangeRaised;
+  Assert.deepEqual(
+    changeEvent.detail.windowIds,
+    [getWindowId(privateWin)],
+    "The event had the correct window id"
+  );
+  Assert.ok(
+    nonPrivateListener.notCalled,
+    "The non-private listener got no recency-change events from the private window"
+  );
+  sortedTabs = privateTabsChanges.getRecentTabs();
+  is(
+    sortedTabs[0],
+    privateWin.gBrowser.selectedTab,
+    "The most-recent tab is the selected tab in the private window"
+  );
+
+  info("Verify switching back to a non-private does the right thing");
+  nonPrivateListener.resetHistory();
+  privateListener.resetHistory();
+
+  tabChangeRaised = BrowserTestUtils.waitForEvent(
+    NonPrivateTabs,
+    "TabRecencyChange"
+  );
+  await SimpleTest.promiseFocus(win1);
+  await tabChangeRaised;
+  if (privateListener.called) {
+    info(`The private listener was called ${privateListener.callCount} times`);
+  }
+  Assert.ok(
+    privateListener.notCalled,
+    "The private listener got no recency-change events for the non-private window"
+  );
+  Assert.ok(
+    nonPrivateListener.called,
+    "Sanity-check the non-private listener got a recency-change event for the non-private window"
+  );
+
+  sortedTabs = privateTabsChanges.getRecentTabs();
+  is(
+    sortedTabs[0],
+    privateWin.gBrowser.selectedTab,
+    "The most-recent private tab is unchanged"
+  );
+
+  sortedTabs = NonPrivateTabs.getRecentTabs();
+  is(
+    sortedTabs[0],
+    win1.gBrowser.selectedTab,
+    "The most-recent non-private tab is the selected tab in the current window"
+  );
+
+  await cleanup("TabRecencyChange");
+  while (win0.gBrowser.tabs.length > 1) {
+    info(
+      "Removing last tab:" +
+        win0.gBrowser.tabs.at(-1).linkedBrowser.currentURI.spec
+    );
+    BrowserTestUtils.removeTab(win0.gBrowser.tabs.at(-1));
+    info("Removed, tabs.length:" + win0.gBrowser.tabs.length);
+  }
+});
+
+add_task(async function test_tabNavigations() {
+  const { windows, cleanup } = await setup("TabChange");
+  const [, win1, privateWin] = windows;
+
+  // also listen for TabRecencyChange events
+  const nonPrivateRecencyListener = sinon.stub();
+  const privateRecencyListener = sinon.stub();
+  privateTabsChanges.addEventListener(
+    "TabRecencyChange",
+    privateRecencyListener
+  );
+  NonPrivateTabs.addEventListener(
+    "TabRecencyChange",
+    nonPrivateRecencyListener
+  );
+
+  info(
+    `Verify navigating in tab generates TabChange & TabRecencyChange events`
+  );
+  let loaded = BrowserTestUtils.browserLoaded(win1.gBrowser.selectedBrowser);
+  win1.gBrowser.selectedBrowser.loadURI(Services.io.newURI(tabURL4), {
+    triggeringPrincipal: Services.scriptSecurityManager.getSystemPrincipal(),
+  });
+  info("waiting for the load into win1 tab to complete");
+  await loaded;
+  info("waiting for listeners to be called");
+  await BrowserTestUtils.waitForCondition(() => {
+    return nonPrivateListener.called && nonPrivateRecencyListener.called;
+  });
+  ok(!privateListener.called, "The private TabChange listener was not called");
+  ok(
+    !privateRecencyListener.called,
+    "The private TabRecencyChange listener was not called"
+  );
+
+  nonPrivateListener.resetHistory();
+  privateListener.resetHistory();
+  nonPrivateRecencyListener.resetHistory();
+  privateRecencyListener.resetHistory();
+
+  // Now verify the same with a private window
+  info(
+    `Verify navigating in private tab generates TabChange & TabRecencyChange events`
+  );
+  ok(
+    !nonPrivateListener.called,
+    "The non-private TabChange listener is not yet called"
+  );
+
+  loaded = BrowserTestUtils.browserLoaded(privateWin.gBrowser.selectedBrowser);
+  privateWin.gBrowser.selectedBrowser.loadURI(
+    Services.io.newURI("about:robots"),
+    {
+      triggeringPrincipal: Services.scriptSecurityManager.getSystemPrincipal(),
+    }
+  );
+  info("waiting for the load into privateWin tab to complete");
+  await loaded;
+  info("waiting for the privateListeners to be called");
+  await BrowserTestUtils.waitForCondition(() => {
+    return privateListener.called && privateRecencyListener.called;
+  });
+  ok(
+    !nonPrivateListener.called,
+    "The non-private TabChange listener was not called"
+  );
+  ok(
+    !nonPrivateRecencyListener.called,
+    "The non-private TabRecencyChange listener was not called"
+  );
+
+  // cleanup
+  privateTabsChanges.removeEventListener(
+    "TabRecencyChange",
+    privateRecencyListener
+  );
+  NonPrivateTabs.removeEventListener(
+    "TabRecencyChange",
+    nonPrivateRecencyListener
+  );
+
+  await cleanup();
+});
+
+add_task(async function test_tabsFromPrivateWindows() {
+  const { cleanup } = await setup("TabChange");
+  const private2Listener = sinon.stub();
+
+  const private2Win = await BrowserTestUtils.openNewBrowserWindow({
+    private: true,
+    waitForTabURL: "about:privatebrowsing",
+  });
+  const private2TabsChanges = getTabsTargetForWindow(private2Win);
+  private2TabsChanges.addEventListener("TabChange", private2Listener);
+  ok(
+    privateTabsChanges !== getTabsTargetForWindow(private2Win),
+    "getTabsTargetForWindow creates a distinct instance for a different private window"
+  );
+
+  await BrowserTestUtils.waitForCondition(() => private2Listener.called);
+
+  ok(
+    !privateListener.called,
+    "No TabChange event was raised by opening a different private window"
+  );
+  privateListener.resetHistory();
+  private2Listener.resetHistory();
+
+  BrowserTestUtils.addTab(private2Win.gBrowser, tabURL1);
+  await BrowserTestUtils.waitForCondition(() => private2Listener.called);
+  ok(
+    !privateListener.called,
+    "No TabChange event was raised by adding tab to a different private window"
+  );
+
+  is(
+    privateTabsChanges.getRecentTabs().length,
+    1,
+    "The recent tab count for the first private window tab target only reports the tabs for its associated windodw"
+  );
+  is(
+    private2TabsChanges.getRecentTabs().length,
+    2,
+    "The recent tab count for a 2nd private window tab target only reports the tabs for its associated windodw"
+  );
+
+  await cleanup("TabChange");
+});

browser/components/firefoxview/tests/browser/browser_opentabs_firefoxview.js

@@ -20,6 +20,10 @@ const fxaDevicesWithCommands = [
   },
 ];
 
+const { NonPrivateTabs } = ChromeUtils.importESModule(
+  "resource:///modules/OpenTabs.sys.mjs"
+);
+
 function getCards(openTabs) {
   return openTabs.shadowRoot.querySelectorAll("view-opentabs-card");
 }
@@ -29,6 +33,64 @@ async function getRowsForCard(card) {
   return card.tabList.rowEls;
 }
 
+async function add_new_tab(URL) {
+  let tabChangeRaised = BrowserTestUtils.waitForEvent(
+    NonPrivateTabs,
+    "TabChange"
+  );
+  let tab = BrowserTestUtils.addTab(gBrowser, URL);
+  // wait so we can reliably compare the tab URL
+  await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+  await tabChangeRaised;
+  return tab;
+}
+
+function getVisibleTabURLs(win = window) {
+  return win.gBrowser.visibleTabs.map(tab => tab.linkedBrowser.currentURI.spec);
+}
+
+function getTabRowURLs(rows) {
+  return Array.from(rows).map(row => row.url);
+}
+
+async function waitUntilRowsMatch(openTabs, cardIndex, expectedURLs) {
+  let card;
+
+  info(
+    "moreMenuSetup: openTabs has openTabsTarget?:" + !!openTabs?.openTabsTarget
+  );
+  //await openTabs.openTabsTarget.readyWindowsPromise;
+  info(
+    `waitUntilRowsMatch, wait for there to be at least ${cardIndex + 1} cards`
+  );
+  await BrowserTestUtils.waitForCondition(() => {
+    if (!openTabs.initialWindowsReady) {
+      info("openTabs.initialWindowsReady isn't true");
+      return false;
+    }
+    try {
+      card = getCards(openTabs)[cardIndex];
+    } catch (ex) {
+      info("Calling getCards produced exception: " + ex.message);
+    }
+    return !!card;
+  }, "Waiting for openTabs to be ready and to get the cards");
+
+  const expectedURLsAsString = JSON.stringify(expectedURLs);
+  info(`Waiting for row URLs to match ${expectedURLs.join(", ")}`);
+  await BrowserTestUtils.waitForMutationCondition(
+    card.shadowRoot,
+    { characterData: true, childList: true, subtree: true },
+    async () => {
+      let rows = await getRowsForCard(card);
+      return (
+        rows.length == expectedURLs.length &&
+        JSON.stringify(getTabRowURLs(rows)) == expectedURLsAsString
+      );
+    }
+  );
+}
+
 async function getContextMenuPanelListForCard(card) {
   let menuContainer = card.shadowRoot.querySelector(
     "view-opentabs-contextmenu"
@@ -56,25 +118,26 @@ async function openContextMenuForItem(tabItem, card) {
   return panelList;
 }
 
-async function moreMenuSetup(document) {
-  await BrowserTestUtils.openNewForegroundTab(gBrowser, TEST_URL2);
-  await BrowserTestUtils.openNewForegroundTab(gBrowser, TEST_URL3);
+async function moreMenuSetup() {
+  await add_new_tab(TEST_URL2);
+  await add_new_tab(TEST_URL3);
 
   // once we've opened a few tabs, navigate to the open tabs section in firefox view
   await clickFirefoxViewButton(window);
-  navigateToCategory(document, "opentabs");
+  const document = window.FirefoxViewHandler.tab.linkedBrowser.contentDocument;
+
+  await navigateToCategoryAndWait(document, "opentabs");
 
   let openTabs = document.querySelector("view-opentabs[name=opentabs]");
+  await openTabs.openTabsTarget.readyWindowsPromise;
 
-  let cards;
-  await TestUtils.waitForCondition(() => {
-    cards = getCards(openTabs);
-    return cards.length == 1;
-  });
+  info("waiting for openTabs' first card rows");
+  await waitUntilRowsMatch(openTabs, 0, getVisibleTabURLs());
+
+  let cards = getCards(openTabs);
   is(cards.length, 1, "There is one open window.");
 
   let rows = await getRowsForCard(cards[0]);
-  is(rows.length, 3, "There are three tabs in the open tabs list.");
 
   let firstTab = rows[0];
 
@@ -90,7 +153,6 @@ async function moreMenuSetup(document) {
 
 add_task(async function test_more_menus() {
   await withFirefoxView({}, async browser => {
-    const { document } = browser.contentWindow;
     let win = browser.ownerGlobal;
     let shown, menuHidden;
 
@@ -101,11 +163,22 @@ add_task(async function test_more_menus() {
       "Selected tab is about:blank"
     );
 
+    info(`Loading ${TEST_URL1} into the selected about:blank tab`);
+    let tabLoaded = BrowserTestUtils.browserLoaded(gBrowser.selectedBrowser);
+
     win.gURLBar.focus();
     win.gURLBar.value = TEST_URL1;
     EventUtils.synthesizeKey("KEY_Enter", {}, win);
+    await tabLoaded;
+
+    info("Waiting for moreMenuSetup to resolve");
+    let [cards, rows] = await moreMenuSetup();
+    Assert.deepEqual(
+      getVisibleTabURLs(),
+      [TEST_URL1, TEST_URL2, TEST_URL3],
+      "Prepared 3 open tabs"
+    );
 
-    let [cards, rows] = await moreMenuSetup(document);
     let firstTab = rows[0];
     // Open the panel list (more menu) from the first list item
     let panelList = await openContextMenuForItem(firstTab, cards[0]);
@@ -136,30 +209,33 @@ add_task(async function test_more_menus() {
     ];
 
     // close a tab via the menu
+    let tabChangeRaised = BrowserTestUtils.waitForEvent(
+      NonPrivateTabs,
+      "TabChange"
+    );
     menuHidden = BrowserTestUtils.waitForEvent(panelList, "hidden");
     panelItemButton.click();
+    info("Waiting for result of closing a tab via the menu");
+    await tabChangeRaised;
     await cards[0].getUpdateComplete();
     await menuHidden;
     await telemetryEvent(contextMenuEvent);
 
-    let visibleTabs = gBrowser.visibleTabs;
-    is(visibleTabs.length, 2, "Expected to now have 2 open tabs");
+    Assert.deepEqual(
+      getVisibleTabURLs(),
+      [TEST_URL2, TEST_URL3],
+      "Got the expected 2 open tabs"
+    );
+
+    let openTabs = cards[0].ownerDocument.querySelector(
+      "view-opentabs[name=opentabs]"
+    );
+    await waitUntilRowsMatch(openTabs, 0, [TEST_URL2, TEST_URL3]);
 
     // Move Tab submenu item
     firstTab = rows[0];
     is(firstTab.url, TEST_URL2, `First tab list item is ${TEST_URL2}`);
 
-    is(
-      visibleTabs[0].linkedBrowser.currentURI.spec,
-      TEST_URL2,
-      `First tab in tab strip is ${TEST_URL2}`
-    );
-    is(
-      visibleTabs[visibleTabs.length - 1].linkedBrowser.currentURI.spec,
-      TEST_URL3,
-      `Last tab in tab strip is ${TEST_URL3}`
-    );
-
     panelList = await openContextMenuForItem(firstTab, cards[0]);
     let moveTabsPanelItem = panelList.querySelector(
       "panel-item[data-l10n-id=fxviewtabrow-move-tab]"
@@ -191,35 +267,27 @@ add_task(async function test_more_menus() {
     // click on the first option, which should be "Move to the end" since
     // this is the first tab
     menuHidden = BrowserTestUtils.waitForEvent(panelList, "hidden");
+    tabChangeRaised = BrowserTestUtils.waitForEvent(
+      NonPrivateTabs,
+      "TabChange"
+    );
     EventUtils.synthesizeKey("KEY_Enter", {});
+    info("Waiting for result of moving a tab via the menu");
     await telemetryEvent(contextMenuEvent);
     await menuHidden;
+    await tabChangeRaised;
 
-    visibleTabs = gBrowser.visibleTabs;
-    is(
-      visibleTabs[0].linkedBrowser.currentURI.spec,
-      TEST_URL3,
-      `First tab in tab strip is now ${TEST_URL3}`
-    );
-    is(
-      visibleTabs[visibleTabs.length - 1].linkedBrowser.currentURI.spec,
-      TEST_URL2,
-      `Last tab in tab strip is now ${TEST_URL2}`
+    Assert.deepEqual(
+      getVisibleTabURLs(),
+      [TEST_URL3, TEST_URL2],
+      "The last tab became the first tab"
     );
 
     // this entire "move tabs" submenu test can be reordered above
     // closing a tab since it very clearly reveals the issues
     // outlined in bug 1852622 when there are 3 or more tabs open
     // and one is moved via the more menus.
-    await BrowserTestUtils.waitForMutationCondition(
-      cards[0].shadowRoot,
-      { characterData: true, childList: true, subtree: true },
-      async () => {
-        rows = await getRowsForCard(cards[0]);
-        firstTab = rows[0];
-        return firstTab.url == TEST_URL3;
-      }
-    );
+    await waitUntilRowsMatch(openTabs, 0, [TEST_URL3, TEST_URL2]);
 
     // Copy Link menu item (copyLink function that's called is a member of Viewpage.mjs)
     panelList = await openContextMenuForItem(firstTab, cards[0]);
@@ -284,7 +352,12 @@ add_task(async function test_send_device_submenu() {
     .callsFake(() => fxaDevicesWithCommands);
 
   await withFirefoxView({}, async browser => {
-    const { document } = browser.contentWindow;
+    // TEST_URL2 is our only tab, left over from previous test
+    Assert.deepEqual(
+      getVisibleTabURLs(),
+      [TEST_URL2],
+      `We initially have a single ${TEST_URL2} tab`
+    );
     let shown;
 
     Services.obs.notifyObservers(null, UIState.ON_UPDATE);

browser/components/firefoxview/tests/browser/browser_opentabs_recency.js

@@ -13,6 +13,9 @@ const tabURL4 = "data:,Tab4";
 
 let gInitialTab;
 let gInitialTabURL;
+const { NonPrivateTabs } = ChromeUtils.importESModule(
+  "resource:///modules/OpenTabs.sys.mjs"
+);
 
 add_setup(function () {
   gInitialTab = gBrowser.selectedTab;
@@ -163,8 +166,14 @@ add_task(async function test_single_window_tabs() {
       browser.contentDocument,
       "visibilitychange"
     );
+
+    let tabChangeRaised = BrowserTestUtils.waitForEvent(
+      NonPrivateTabs,
+      "TabRecencyChange"
+    );
     await BrowserTestUtils.switchTab(gBrowser, gBrowser.visibleTabs[0]);
     await promiseHidden;
+    await tabChangeRaised;
   });
 
   // and check the results in the open tabs section of Recent Browsing
@@ -178,6 +187,7 @@ add_task(async function test_single_window_tabs() {
 add_task(async function test_multiple_window_tabs() {
   const fxViewURL = getFirefoxViewURL();
   const win1 = window;
+  let tabChangeRaised;
   await prepareOpenTabs([tabURL1, tabURL2]);
   const win2 = await BrowserTestUtils.openNewBrowserWindow();
   await prepareOpenTabs([tabURL3, tabURL4], win2);
@@ -196,6 +206,10 @@ add_task(async function test_multiple_window_tabs() {
     );
 
     info("Switching to first tab (tab3) in win2");
+    tabChangeRaised = BrowserTestUtils.waitForEvent(
+      NonPrivateTabs,
+      "TabRecencyChange"
+    );
     let promiseHidden = BrowserTestUtils.waitForEvent(
       browser.contentDocument,
       "visibilitychange"
@@ -209,6 +223,7 @@ add_task(async function test_multiple_window_tabs() {
       tabURL3,
       `The selected tab in window 2 is ${tabURL3}`
     );
+    await tabChangeRaised;
     await promiseHidden;
   });
 
@@ -220,7 +235,12 @@ add_task(async function test_multiple_window_tabs() {
   });
 
   info("Focusing win1, where tab2 should be selected");
+  tabChangeRaised = BrowserTestUtils.waitForEvent(
+    NonPrivateTabs,
+    "TabRecencyChange"
+  );
   await SimpleTest.promiseFocus(win1);
+  await tabChangeRaised;
   Assert.equal(
     tabUrl(win1.gBrowser.selectedTab),
     tabURL2,
@@ -239,12 +259,17 @@ add_task(async function test_multiple_window_tabs() {
       browser.contentDocument,
       "visibilitychange"
     );
+    tabChangeRaised = BrowserTestUtils.waitForEvent(
+      NonPrivateTabs,
+      "TabRecencyChange"
+    );
     info("Switching to first visible tab (tab1) in win1");
     await BrowserTestUtils.switchTab(
       win1.gBrowser,
       win1.gBrowser.visibleTabs[0]
     );
     await promiseHidden;
+    await tabChangeRaised;
   });
 
   // check result in the fxview in the 1st window
@@ -262,27 +287,41 @@ add_task(async function test_windows_activation() {
   const win1 = window;
   await prepareOpenTabs([tabURL1], win1);
   let fxViewTab;
+  let tabChangeRaised;
   info("switch to firefox-view and leave it selected");
   await openFirefoxViewTab(win1).then(tab => (fxViewTab = tab));
 
   const win2 = await BrowserTestUtils.openNewBrowserWindow();
   await prepareOpenTabs([tabURL2], win2);
+
   const win3 = await BrowserTestUtils.openNewBrowserWindow();
   await prepareOpenTabs([tabURL3], win3);
+  await tabChangeRaised;
 
+  tabChangeRaised = BrowserTestUtils.waitForEvent(
+    NonPrivateTabs,
+    "TabRecencyChange"
+  );
   await SimpleTest.promiseFocus(win1);
+  await tabChangeRaised;
 
   const browser = fxViewTab.linkedBrowser;
   await checkTabList(browser, [tabURL3, tabURL2, tabURL1]);
 
   info("switch to win2 and confirm its selected tab becomes most recent");
+  tabChangeRaised = BrowserTestUtils.waitForEvent(
+    NonPrivateTabs,
+    "TabRecencyChange"
+  );
   await SimpleTest.promiseFocus(win2);
+  await tabChangeRaised;
   await checkTabList(browser, [tabURL2, tabURL3, tabURL1]);
   await cleanup(win2, win3);
 });
 
 add_task(async function test_minimize_restore_windows() {
   const win1 = window;
+  let tabChangeRaised;
   await prepareOpenTabs([tabURL1, tabURL2]);
   const win2 = await BrowserTestUtils.openNewBrowserWindow();
   await prepareOpenTabs([tabURL3, tabURL4], win2);
@@ -298,19 +337,29 @@ add_task(async function test_minimize_restore_windows() {
       browser.contentDocument,
       "visibilitychange"
     );
+    tabChangeRaised = BrowserTestUtils.waitForEvent(
+      NonPrivateTabs,
+      "TabRecencyChange"
+    );
     info("Switching to the first tab (tab3) in 2nd window");
     await BrowserTestUtils.switchTab(
       win2.gBrowser,
       win2.gBrowser.visibleTabs[0]
     );
     await promiseHidden;
+    await tabChangeRaised;
   });
 
   // then minimize the window, focusing the 1st window
   info("Minimizing win2, leaving tab 3 selected");
+  tabChangeRaised = BrowserTestUtils.waitForEvent(
+    NonPrivateTabs,
+    "TabRecencyChange"
+  );
   await minimizeWindow(win2);
   info("Focusing win1, where tab2 is selected - making it most recent");
   await SimpleTest.promiseFocus(win1);
+  await tabChangeRaised;
 
   Assert.equal(
     tabUrl(win1.gBrowser.selectedTab),
@@ -325,8 +374,13 @@ add_task(async function test_minimize_restore_windows() {
     info(
       "Restoring win2 and focusing it - which should make its selected tab most recent"
     );
+    tabChangeRaised = BrowserTestUtils.waitForEvent(
+      NonPrivateTabs,
+      "TabRecencyChange"
+    );
     await restoreWindow(win2);
     await SimpleTest.promiseFocus(win2);
+    await tabChangeRaised;
 
     info(
       "Checking tab order in fxview in win1, to confirm tab3 is most recent"

browser/components/firefoxview/tests/browser/head.js

@@ -60,6 +60,7 @@ const URLs = [
   "https://example.net/",
   "https://example.org/",
   "about:robots",
+  "https://www.mozilla.org/",
 ];
 
 const syncedTabsData1 = [

browser/components/firefoxview/viewpage.mjs

@@ -70,10 +70,9 @@ export class ViewPageContent extends MozLitElement {
     return window.browsingContext.embedderWindowGlobal.browsingContext.window;
   }
 
-  getBrowserTab() {
-    return this.getWindow().gBrowser.getTabForBrowser(
-      window.browsingContext.embedderElement
-    );
+  get isSelectedBrowserTab() {
+    const { gBrowser } = this.getWindow();
+    return gBrowser.selectedBrowser.browsingContext == window.browsingContext;
   }
 
   copyLink(e) {

browser/components/newtab/lib/AboutPreferences.jsm

@@ -160,6 +160,8 @@ class AboutPreferences {
     document.l10n.setAttributes(homeHeader, "home-prefs-content-header2");
 
     const homeDescription = createAppend("description", contentsGroup);
+    homeDescription.classList.add("description-deemphasized");
+
     document.l10n.setAttributes(
       homeDescription,
       "home-prefs-content-description2"
@@ -228,10 +230,10 @@ class AboutPreferences {
       const detailVbox = createAppend("vbox", sectionVbox);
       detailVbox.classList.add("indent");
       if (descString) {
-        const label = createAppend("label", detailVbox);
-        label.classList.add("indent");
+        const description = createAppend("description", detailVbox);
+        description.classList.add("indent", "text-deemphasized");
         document.l10n.setAttributes(
-          label,
+          description,
           getString(descString),
           descString.values
         );
@@ -240,8 +242,8 @@ class AboutPreferences {
         if (rowsPref && maxRows) {
           const detailHbox = createAppend("hbox", detailVbox);
           detailHbox.setAttribute("align", "center");
-          label.setAttribute("flex", 1);
-          detailHbox.appendChild(label);
+          description.setAttribute("flex", 1);
+          detailHbox.appendChild(description);
 
           // Add box so the search tooltip is positioned correctly
           const tooltipBox = createAppend("hbox", detailHbox);

browser/components/preferences/experimental.inc.xhtml

@@ -12,6 +12,7 @@
       data-category="paneExperimental">
   <html:h1 style="flex: 1;" data-l10n-id="pane-experimental-title"/>
   <label><html:h2 id="pane-experimental-subtitle" data-l10n-id="pane-experimental-subtitle"/></label>
+  <html:p data-l10n-id="pane-experimental-description2" class="description-deemphasized"/>
   <hbox pack="end">
     <button id="experimentalCategory-reset"
             class="accessory-button"
@@ -25,13 +26,13 @@
   <label class="search-header" hidden="true">
     <html:h2 id="pane-experimental-search-results-header" data-l10n-id="pane-experimental-search-results-header"/>
   </label>
-  <html:p data-l10n-id="pane-experimental-description2"/>
+  <html:p data-l10n-id="pane-experimental-description2" class="description-deemphasized"/>
 </groupbox>
 </html:template>
 
 <html:template id="template-featureGate">
     <html:div class="featureGate">
         <checkbox class="featureGateCheckbox"/>
-        <label class="featureGateDescription"/>
+        <description class="text-deemphasized featureGateDescription"/>
     </html:div>
 </html:template>

browser/components/preferences/home.inc.xhtml

@@ -23,7 +23,7 @@
           data-category="paneHome"
           hidden="true">
   <label><html:h2 data-l10n-id="home-new-windows-tabs-header"/></label>
-  <description data-l10n-id="home-new-windows-tabs-description2" />
+  <description class="description-deemphasized" data-l10n-id="home-new-windows-tabs-description2" />
 
   <hbox id="homepageAndNewWindowsOption" align="center" data-subcategory="homeOverride">
     <label control="homeMode" data-l10n-id="home-homepage-mode-label" flex="1" />

browser/components/preferences/main.inc.xhtml

@@ -158,7 +158,7 @@
 <groupbox id="webAppearanceGroup" data-category="paneGeneral" hidden="true">
   <html:h2 data-l10n-id="preferences-web-appearance-header"/>
   <html:div id="webAppearanceSettings">
-    <description data-l10n-id="preferences-web-appearance-description"/>
+    <description class="description-deemphasized" data-l10n-id="preferences-web-appearance-description"/>
     <html:div id="web-appearance-override-warning" class="info-box-container">
       <html:div class="info-icon-container">
         <html:img class="info-icon"/>
@@ -442,7 +442,7 @@
 
 <groupbox id="applicationsGroup" data-category="paneGeneral" hidden="true">
   <label><html:h2 data-l10n-id="applications-header"/></label>
-  <description data-l10n-id="applications-description"/>
+  <description class="description-deemphasized" data-l10n-id="applications-description"/>
   <search-textbox id="filter" flex="1"
                   data-l10n-id="applications-filter"
                   data-l10n-attrs="placeholder"
@@ -458,8 +458,8 @@
   </listheader>
   <richlistbox id="handlersView"
                preference="pref.downloads.disable_button.edit_actions"/>
-  <description id="handleNewFileTypesDesc"
-               data-l10n-id="applications-handle-new-file-types-description"/>
+  <label id="handleNewFileTypesDesc"
+         data-l10n-id="applications-handle-new-file-types-description"/>
   <radiogroup id="handleNewFileTypes"
               preference="browser.download.always_ask_before_handling_new_types">
     <radio id="saveForNewTypes"
@@ -496,12 +496,12 @@
 <groupbox id="updateApp" data-category="paneGeneral" hidden="true">
   <label class="search-header" hidden="true"><html:h2 data-l10n-id="update-application-title"/></label>
 
-  <label data-l10n-id="update-application-description"/>
+  <description class="description-deemphasized" data-l10n-id="update-application-description"/>
   <hbox align="center">
     <vbox flex="1">
-      <description id="updateAppInfo">
+      <html:span id="updateAppInfo">
         <html:a id="releasenotes" target="_blank" data-l10n-name="learn-more" class="learnMore text-link" hidden="true"/>
-      </description>
+      </html:span>
       <description id="distribution" class="text-blurb" hidden="true"/>
       <description id="distributionId" class="text-blurb" hidden="true"/>
     </vbox>
@@ -621,7 +621,7 @@
 #endif
 
 #ifdef MOZ_UPDATER
-  <description id="updateAllowDescription" data-l10n-id="update-application-allow-description"></description>
+  <label id="updateAllowDescription" data-l10n-id="update-application-allow-description"></label>
   <vbox id="updateSettingsContainer" class="info-box-container">
     <radiogroup id="updateRadioGroup">
       <radio id="autoDesktop"

browser/components/preferences/moreFromMozilla.inc.xhtml

@@ -12,7 +12,7 @@
     hidden="true"
     data-category="paneMoreFromMozilla">
     <h1 class="title" data-l10n-id="more-from-moz-title"/>
-    <p class="subtitle" data-l10n-id="more-from-moz-subtitle"/>
+    <p class="subtitle description-deemphasized" data-l10n-id="more-from-moz-subtitle"/>
   </div>
   <div id="moreFromMozillaCategory"
     data-category="paneMoreFromMozilla"
@@ -27,7 +27,7 @@
     <div>
       <h2 class="product-title"/>
       <div class="product-description-box">
-        <div class="description"/>
+        <div class="description description-deemphasized"/>
         <a class="text-link" target="_blank" hidden="true"/>
       </div>
     </div>

browser/components/preferences/privacy.inc.xhtml

@@ -402,8 +402,8 @@
 
   <hbox data-subcategory="sitedata" align="baseline">
     <vbox flex="1">
-      <description class="description-with-side-element" flex="1">
-        <html:span id="totalSiteDataSize" class="tail-with-learn-more section-description"></html:span>
+      <description class="description-with-side-element description-deemphasized" flex="1">
+        <html:span id="totalSiteDataSize" class="tail-with-learn-more"></html:span>
         <html:a is="moz-support-link"
                 id="siteDataLearnMoreLink"
                 data-l10n-id="sitedata-learn-more"
@@ -463,8 +463,8 @@
   <label><html:h2 data-l10n-id="cookie-banner-blocker-header" /></label>
   <vbox flex="1">
     <hbox>
-      <description>
-        <html:span id="cookieBannerReductionExplanation" class="tail-with-learn-more section-description" data-l10n-id="cookie-banner-blocker-description" ></html:span>
+      <description class="description-deemphasized">
+        <html:span id="cookieBannerReductionExplanation" class="tail-with-learn-more" data-l10n-id="cookie-banner-blocker-description" ></html:span>
         <html:a is="moz-support-link" id="cookieBannerHandlingLearnMore" class="learnMore"  data-l10n-id="cookie-banner-learn-more" support-page="cookie-banner-reduction"/>
       </description>
     </hbox>
@@ -713,10 +713,10 @@
   <!-- The hbox around the buttons is to compute the search tooltip position properly -->
   <vbox>
     <hbox id="locationSettingsRow" align="center" role="group" aria-labelledby="locationPermissionsLabel">
-      <description flex="1">
+      <hbox flex="1">
         <image class="geo-icon permission-icon" />
         <label id="locationPermissionsLabel" data-l10n-id="permissions-location"/>
-      </description>
+      </hbox>
       <hbox pack="end">
         <button id="locationSettingsButton"
                 is="highlightable-button"
@@ -734,10 +734,10 @@
     </hbox>
 
     <hbox id="cameraSettingsRow" align="center" role="group" aria-labelledby="cameraPermissionsLabel">
-      <description flex="1">
+      <hbox flex="1">
         <image class="camera-icon permission-icon" />
         <label id="cameraPermissionsLabel" data-l10n-id="permissions-camera"/>
-      </description>
+      </hbox>
       <hbox pack="end">
         <button id="cameraSettingsButton"
                 is="highlightable-button"
@@ -755,10 +755,10 @@
     </hbox>
 
     <hbox id="microphoneSettingsRow" align="center" role="group" aria-labelledby="microphonePermissionsLabel">
-      <description flex="1">
+      <hbox flex="1">
         <image class="microphone-icon permission-icon" />
         <label id="microphonePermissionsLabel" data-l10n-id="permissions-microphone"/>
-      </description>
+      </hbox>
       <hbox pack="end">
         <button id="microphoneSettingsButton"
                 is="highlightable-button"
@@ -776,10 +776,10 @@
     </hbox>
 
     <hbox id="speakerSettingsRow" align="center" role="group" aria-labelledby="speakerPermissionsLabel">
-      <description flex="1">
+      <hbox flex="1">
         <image class="speaker-icon permission-icon" />
         <label id="speakerPermissionsLabel" data-l10n-id="permissions-speaker"/>
-      </description>
+      </hbox>
       <hbox pack="end">
         <button id="speakerSettingsButton"
                 is="highlightable-button"
@@ -795,7 +795,7 @@
     </hbox>
 
     <hbox id="notificationSettingsRow" align="center" role="group" aria-labelledby="notificationPermissionsLabel">
-      <description flex="1">
+      <hbox flex="1">
         <image class="desktop-notification-icon permission-icon" />
         <label id="notificationPermissionsLabel"
                class="tail-with-learn-more"
@@ -806,7 +806,7 @@
                 data-l10n-id="permissions-notification-link"
                 support-page="push"
         />
-      </description>
+      </hbox>
       <hbox pack="end">
         <button id="notificationSettingsButton"
                 is="highlightable-button"
@@ -828,11 +828,11 @@
     </vbox>
 
     <hbox id="autoplaySettingsRow" align="center" role="group" aria-labelledby="autoplayPermissionsLabel">
-      <description flex="1">
+      <hbox flex="1">
         <image class="autoplay-icon permission-icon" />
         <label id="autoplayPermissionsLabel"
                data-l10n-id="permissions-autoplay"/>
-      </description>
+      </hbox>
       <hbox pack="end">
         <button id="autoplaySettingsButton"
                 is="highlightable-button"
@@ -848,10 +848,10 @@
     </hbox>
 
     <hbox id="xrSettingsRow" align="center" role="group" aria-labelledby="xrPermissionsLabel">
-      <description flex="1">
+      <hbox flex="1">
         <image class="xr-icon permission-icon" />
         <label id="xrPermissionsLabel" data-l10n-id="permissions-xr"/>
-      </description>
+      </hbox>
       <hbox pack="end">
         <button id="xrSettingsButton"
                 is="highlightable-button"
@@ -919,8 +919,8 @@
 <groupbox id="dataCollectionGroup" data-category="panePrivacy" hidden="true">
   <label class="search-header" hidden="true"><html:h2 data-l10n-id="collection-header2" data-l10n-attrs="searchkeywords"/></label>
 
-  <description>
-    <label class="tail-with-learn-more section-description" data-l10n-id="collection-description"/>
+  <description class="description-deemphasized">
+    <html:span class="tail-with-learn-more" data-l10n-id="collection-description"/>
     <html:a id="dataCollectionPrivacyNotice"
            class="learnMore"
            data-l10n-id="collection-privacy-notice"/>
@@ -940,7 +940,7 @@
     </description>
   </hbox>
   <vbox data-subcategory="reports">
-    <description flex="1">
+    <html:span flex="1">
       <checkbox id="submitHealthReportBox"
                 data-l10n-id="collection-health-report"
                 class="tail-with-learn-more"/>
@@ -960,7 +960,7 @@
           />
         </hbox>
       </vbox>
-    </description>
+    </html:span>
 #ifndef MOZ_TELEMETRY_REPORTING
   <description id="TelemetryDisabledDesc"
     class="indent tip-caption" control="telemetryGroup"
@@ -1118,7 +1118,7 @@
 <groupbox id="httpsOnlyBox" data-category="panePrivacy" hidden="true">
   <label><html:h2 data-l10n-id="httpsonly-header"/></label>
   <vbox data-subcategory="httpsonly" flex="1">
-    <label id="httpsOnlyDescription" class="section-description" data-l10n-id="httpsonly-description"/>
+    <description id="httpsOnlyDescription" class="description-deemphasized" data-l10n-id="httpsonly-description"/>
     <html:a is="moz-support-link"
             id="httpsOnlyLearnMore"
             class="learnMore"
@@ -1162,7 +1162,7 @@
 <groupbox id="dohBox" data-category="panePrivacy" data-subcategory="doh" hidden="true" class="highlighting-group">
   <label class="search-header" searchkeywords="doh trr" hidden="true"><html:h2 data-l10n-id="preferences-doh-header"/></label>
   <vbox flex="1">
-    <html:span id="dohDescription" class="tail-with-learn-more" data-l10n-id="preferences-doh-description2"></html:span>
+    <description id="dohDescription" class="tail-with-learn-more description-deemphasized" data-l10n-id="preferences-doh-description2"></description>
     <html:a is="moz-support-link"
             id="dohLearnMore"
             class="learnMore"

browser/components/preferences/search.inc.xhtml

@@ -14,7 +14,7 @@
     <!-- Default Search Engine -->
     <groupbox id="defaultEngineGroup" data-category="paneSearch" hidden="true">
       <label><html:h2 data-l10n-id="search-engine-default-header" id="search-engine-default-header" /></label>
-      <description class="section-description" data-l10n-id="search-engine-default-desc-2" id="search-engine-default-desc-2" />
+      <description class="description-deemphasized" data-l10n-id="search-engine-default-desc-2" id="search-engine-default-desc-2" />
       <hbox>
         <menulist id="defaultEngine" aria-labelledby="search-engine-default-header" aria-describedby="search-engine-default-desc-2">
           <menupopup/>
@@ -40,7 +40,7 @@
     <groupbox id="searchSuggestionsGroup" data-category="paneSearch" hidden="true">
       <label><html:h2 data-l10n-id="search-suggestions-header" /></label>
       <description id="searchSuggestionsDesc"
-                   class="section-description"
+                   class="description-deemphasized"
                    data-l10n-id="search-suggestions-desc" />
 
       <checkbox id="suggestionsInSearchFieldsCheckbox"
@@ -71,7 +71,7 @@
               hidden="true"
               data-subcategory="locationBar">
       <label><html:h2 id="locationBarGroupHeader" data-l10n-id="addressbar-header"/></label>
-      <label id="locationBarSuggestionLabel" class="section-description" data-l10n-id="addressbar-suggest"/>
+      <label id="locationBarSuggestionLabel" class="description-deemphasized" data-l10n-id="addressbar-suggest"/>
       <checkbox id="historySuggestion" data-l10n-id="addressbar-locbar-history-option"
                 preference="browser.urlbar.suggest.history"/>
       <checkbox id="bookmarkSuggestion" data-l10n-id="addressbar-locbar-bookmarks-option"
@@ -164,7 +164,7 @@
 
     <groupbox id="oneClickSearchProvidersGroup" data-category="paneSearch" hidden="true">
       <label><html:h2 data-l10n-id="search-one-click-header2" /></label>
-      <description class="section-description" data-l10n-id="search-one-click-desc" />
+      <description class="description-deemphasized" data-l10n-id="search-one-click-desc" />
 
       <tree id="engineList" flex="1" rows="11" hidecolumnpicker="true" editable="true"
             seltype="single" allowunderflowscroll="true">

browser/components/preferences/sync.inc.xhtml

@@ -19,7 +19,7 @@
     <hbox>
       <vbox flex="1">
         <label id="noFxaCaption"><html:h2 data-l10n-id="sync-signedout-caption"/></label>
-        <description id="noFxaDescription" flex="1" data-l10n-id="sync-signedout-description2"/>
+        <description id="noFxaDescription" class="description-deemphasized" flex="1" data-l10n-id="sync-signedout-description2"/>
       </vbox>
       <vbox>
         <image class="fxaSyncIllustration"/>

browser/components/reportbrokensite/test/browser/browser_antitracking_data_sent.js

@@ -49,6 +49,9 @@ add_task(async function testSendButton() {
 });
 
 add_task(async function testSendingMoreInfo() {
+  ensureReportBrokenSitePreffedOn();
+  ensureSendMoreInfoEnabled();
+
   const win = await BrowserTestUtils.openNewBrowserWindow({ private: true });
   const blockedPromise = waitForContentBlockingEvent(4, win);
   const tab = await openTab(REPORTABLE_PAGE_URL3, win);

browser/components/urlbar/UrlbarView.sys.mjs

@@ -2669,24 +2669,25 @@ export class UrlbarView {
             },
           });
           actionNode.appendChild(textModeLabel);
-        }
 
-        let iconModeLabel = this.#createElement("div");
-        iconModeLabel.classList.add("urlbarView-userContext-iconMode");
-        actionNode.appendChild(iconModeLabel);
-        if (identity.icon) {
-          let userContextIcon = this.#createElement("img");
-          userContextIcon.classList.add("urlbarView-userContext-icon");
+          let iconModeLabel = this.#createElement("div");
+          iconModeLabel.classList.add("urlbarView-userContext-iconMode");
+          actionNode.appendChild(iconModeLabel);
+          if (identity.icon) {
+            let userContextIcon = this.#createElement("img");
+            userContextIcon.classList.add("urlbarView-userContext-icon");
 
-          userContextIcon.classList.add("identity-icon-" + identity.icon);
-          userContextIcon.src =
-            "resource://usercontext-content/" + identity.icon + ".svg";
-          this.#setElementL10n(iconModeLabel, {
-            id: "urlbar-result-action-switch-tab",
-          });
-          iconModeLabel.appendChild(userContextIcon);
+            userContextIcon.classList.add("identity-icon-" + identity.icon);
+            userContextIcon.setAttribute("alt", label);
+            userContextIcon.src =
+              "resource://usercontext-content/" + identity.icon + ".svg";
+            this.#setElementL10n(iconModeLabel, {
+              id: "urlbar-result-action-switch-tab",
+            });
+            iconModeLabel.appendChild(userContextIcon);
+          }
+          actionNode.setAttribute("tooltiptext", label);
         }
-        actionNode.setAttribute("tooltiptext", label);
       }
     } else {
       actionNode.classList.remove("urlbarView-userContext");

browser/locales/l10n-changesets.json

@@ -321,7 +321,7 @@
             "win64-aarch64-devedition",
             "win64-devedition"
         ],
-        "revision": "51810469d2ed19df5cb49082c989f8fcf65fcc4d"
+        "revision": "10b19832d6f9c6bad12df2d06c270e15122c9e13"
     },
     "cy": {
         "pin": false,
@@ -339,7 +339,7 @@
             "win64-aarch64-devedition",
             "win64-devedition"
         ],
-        "revision": "4024c7ecbd1a45d4248a194e16af61c07b0665c5"
+        "revision": "d0a11c0d32ce900fd4e7fd7acbf7f5fdd9dc3391"
     },
     "da": {
         "pin": false,
@@ -429,7 +429,7 @@
             "win64-aarch64-devedition",
             "win64-devedition"
         ],
-        "revision": "a92a63fb79ce056eceaadc5e6009f8615166db24"
+        "revision": "3e7b7d6fc79e7aa7a522cd4e715d627d36b7da48"
     },
     "en-GB": {
         "pin": false,
@@ -483,7 +483,7 @@
             "win64-aarch64-devedition",
             "win64-devedition"
         ],
-        "revision": "144e2857d4416a9f77881758c821b70073641776"
+        "revision": "e48d80a1eb27d4f2f61cbb5590213aca4bd086bc"
     },
     "es-CL": {
         "pin": false,
@@ -501,7 +501,7 @@
             "win64-aarch64-devedition",
             "win64-devedition"
         ],
-        "revision": "8dc0bc0e263866f475aba07aeffac4ac2c33b9fd"
+        "revision": "99a4be2c74839f57a06ae23092a6ed6a6456be16"
     },
     "es-ES": {
         "pin": false,
@@ -663,7 +663,7 @@
             "win64-aarch64-devedition",
             "win64-devedition"
         ],
-        "revision": "acee7581e90605d397358fb1e977d6592b98ee9f"
+        "revision": "de54777091065d2e2586e14100291443889a87d1"
     },
     "fy-NL": {
         "pin": false,
@@ -681,7 +681,7 @@
             "win64-aarch64-devedition",
             "win64-devedition"
         ],
-        "revision": "912eca8abda68ea89fe3828b90be025d12c0e06a"
+        "revision": "7ecdf7006c660ad24c34b32832fbbc9064f4bedb"
     },
     "ga-IE": {
         "pin": false,
@@ -933,7 +933,7 @@
             "win64-aarch64-devedition",
             "win64-devedition"
         ],
-        "revision": "211c31bd4d44345e58d0b60e9fd3f291f00b42ec"
+        "revision": "5ade332ab27a99ae3cae7b1a3c9a2f8719fb6011"
     },
     "is": {
         "pin": false,
@@ -951,7 +951,7 @@
             "win64-aarch64-devedition",
             "win64-devedition"
         ],
-        "revision": "9013b283a10d3221416e41f3286f04362fd101a2"
+        "revision": "b1fcc013b9532f950b76284fb0d12a3b1ce21d82"
     },
     "it": {
         "pin": false,
@@ -969,7 +969,7 @@
             "win64-aarch64-devedition",
             "win64-devedition"
         ],
-        "revision": "435ddfa85768ca5a615effa437ce6ce042b0cfad"
+        "revision": "274739ede703030e4c0e2b5969fdc8facc6bd829"
     },
     "ja": {
         "pin": false,
@@ -1047,7 +1047,7 @@
             "win64-aarch64-devedition",
             "win64-devedition"
         ],
-        "revision": "bb7643734330ea9c8ba8c4114450a15345e786b6"
+        "revision": "3badac8b94f60804b0a35088b0ea5c14ecfec957"
     },
     "km": {
         "pin": false,
@@ -1335,7 +1335,7 @@
             "win64-aarch64-devedition",
             "win64-devedition"
         ],
-        "revision": "91e981553eb44036c937a0444fb8094060e13aa3"
+        "revision": "eaeaca90356b1cb1befb9b380fa7157a6b159197"
     },
     "nn-NO": {
         "pin": false,
@@ -1353,7 +1353,7 @@
             "win64-aarch64-devedition",
             "win64-devedition"
         ],
-        "revision": "e64c7baf0035a40ef2924db1cea53a2408bcc6b0"
+        "revision": "3d741e78526872af2b3aa9e770f2ae5fce12314c"
     },
     "oc": {
         "pin": false,
@@ -1371,7 +1371,7 @@
             "win64-aarch64-devedition",
             "win64-devedition"
         ],
-        "revision": "6cf67388ceb42112f9f0173439b3fa056f9cd1de"
+        "revision": "cef833d7b2ed57de9d8cd3ff36dde53f82a6fd08"
     },
     "pa-IN": {
         "pin": false,
@@ -1425,7 +1425,7 @@
             "win64-aarch64-devedition",
             "win64-devedition"
         ],
-        "revision": "a21f1f89a92766e2e66bb3e22e6c711c4e20cd95"
+        "revision": "fdc76da512eb2bc09ebd60ab5879884624583d3f"
     },
     "pt-PT": {
         "pin": false,
@@ -1641,7 +1641,7 @@
             "win64-aarch64-devedition",
             "win64-devedition"
         ],
-        "revision": "7647b135719899ee039bfa57ed5993011e58809a"
+        "revision": "190390b8eba1b48fa2e34ea8c077ee155e6b92a2"
     },
     "son": {
         "pin": false,
@@ -1875,7 +1875,7 @@
             "win64-aarch64-devedition",
             "win64-devedition"
         ],
-        "revision": "61e1aae8dbe301375d8c12378cd01f7d040eae4d"
+        "revision": "756a56528941a62738659cad4ab2d8858678528e"
     },
     "ur": {
         "pin": false,

browser/modules/EveryWindow.sys.mjs

@@ -37,6 +37,15 @@ function callForEveryWindow(callback) {
 }
 
 export const EveryWindow = {
+  /**
+   * The current list of all browser windows whose delayedStartupPromise has resolved
+   */
+  get readyWindows() {
+    return Array.from(Services.wm.getEnumerator("navigator:browser")).filter(
+      win => win.gBrowserInit?.delayedStartupFinished
+    );
+  },
+
   /**
    * Registers init and uninit functions to be called on every window.
    *

browser/themes/shared/preferences/preferences.css

@@ -90,10 +90,6 @@ html|select {
   user-select: none;
 }
 
-.section-description {
-  color: var(--text-color-deemphasized);
-}
-
 /* Buttons get a default min-width in XUL. When they also have flex, they will
  * be large enough anyway, and we don't want them to become smaller than their inner
  * text which would then overflow the button. Set min-width back to auto for that:
@@ -108,6 +104,10 @@ label {
   margin: 0;
 }
 
+.description-deemphasized {
+  color: var(--text-color-deemphasized);
+}
+
 .tip-caption {
   font-size: .9em;
   color: var(--text-color-deemphasized);
@@ -1247,7 +1247,6 @@ richlistitem .text-link:hover {
 }
 
 #moreFromMozillaCategory-header .subtitle {
-  color: var(--in-content-text-color);
   margin-block-end: 24px;
   line-height: 1.4em;
 }

caps/BasePrincipal.cpp

@@ -28,6 +28,8 @@
 #include "mozilla/Components.h"
 #include "mozilla/dom/StorageUtils.h"
 #include "mozilla/dom/StorageUtils.h"
+#include "mozilla/JSONStringWriteFuncs.h"
+#include "mozilla/JSONWriter.h"
 #include "nsIURL.h"
 #include "nsEffectiveTLDService.h"
 #include "nsIURIMutator.h"
@@ -42,17 +44,16 @@
 #include "nsIURIMutator.h"
 #include "mozilla/PermissionManager.h"
 
-#include "json/json.h"
 #include "nsSerializationHelper.h"
 
-namespace mozilla {
+#include "js/JSON.h"
+#include "ContentPrincipalJSONHandler.h"
+#include "ExpandedPrincipalJSONHandler.h"
+#include "NullPrincipalJSONHandler.h"
+#include "PrincipalJSONHandler.h"
+#include "SubsumedPrincipalJSONHandler.h"
 
-const char* BasePrincipal::JSONEnumKeyStrings[4] = {
-    "0",
-    "1",
-    "2",
-    "3",
-};
+namespace mozilla {
 
 BasePrincipal::BasePrincipal(PrincipalKind aKind,
                              const nsACString& aOriginNoSuffix,
@@ -141,113 +142,183 @@ BasePrincipal::GetSiteOriginNoSuffix(nsACString& aSiteOrigin) {
   return GetOriginNoSuffix(aSiteOrigin);
 }
 
-// Returns the inner Json::value of the serialized principal
-// Example input and return values:
-// Null principal:
-// {"0":{"0":"moz-nullprincipal:{56cac540-864d-47e7-8e25-1614eab5155e}"}} ->
-// {"0":"moz-nullprincipal:{56cac540-864d-47e7-8e25-1614eab5155e}"}
-//
-// Content principal:
-// {"1":{"0":"https://mozilla.com"}} -> {"0":"https://mozilla.com"}
-//
-// Expanded principal:
-// {"2":{"0":"<base64principal1>,<base64principal2>"}} ->
-// {"0":"<base64principal1>,<base64principal2>"}
-//
-// System principal:
-// {"3":{}} -> {}
-// The aKey passed in also returns the corresponding PrincipalKind enum
-//
-// Warning: The Json::Value* pointer is into the aRoot object
-static const Json::Value* GetPrincipalObject(const Json::Value& aRoot,
-                                             int& aOutPrincipalKind) {
-  const Json::Value::Members members = aRoot.getMemberNames();
-  // We only support one top level key in the object
-  if (members.size() != 1) {
-    return nullptr;
+template <typename HandlerTypesT>
+bool ContainerPrincipalJSONHandler<HandlerTypesT>::ProcessInnerResult(
+    bool aResult) {
+  if (!aResult) {
+    NS_WARNING("Failed to parse inner object");
+    mState = State::Error;
+    return false;
   }
-  // members[0] here is the "0", "1", "2", "3" principalKind
-  // that is the top level of the serialized JSON principal
-  const std::string stringPrincipalKind = members[0];
-
-  // Next we take the string value from the JSON
-  // and convert it into the int for the BasePrincipal::PrincipalKind enum
-
-  // Verify that the key is within the valid range
-  int principalKind = std::stoi(stringPrincipalKind);
-  MOZ_ASSERT(BasePrincipal::eNullPrincipal == 0,
-             "We need to rely on 0 being a bounds check for the first "
-             "principal kind.");
-  if (principalKind < 0 || principalKind > BasePrincipal::eKindMax) {
-    return nullptr;
-  }
-  MOZ_ASSERT(principalKind == BasePrincipal::eNullPrincipal ||
-             principalKind == BasePrincipal::eContentPrincipal ||
-             principalKind == BasePrincipal::eExpandedPrincipal ||
-             principalKind == BasePrincipal::eSystemPrincipal);
-  aOutPrincipalKind = principalKind;
-
-  if (!aRoot[stringPrincipalKind].isObject()) {
-    return nullptr;
-  }
-
-  // Return the inner value of the principal object
-  return &aRoot[stringPrincipalKind];
+  return true;
 }
 
-// Accepts the JSON inner object without the wrapping principalKind
-// (See GetPrincipalObject for the inner object response examples)
-// Creates an array of KeyVal objects that are all defined on the principal
-// Each principal type (null, content, expanded) has a KeyVal that stores the
-// fields of the JSON
-//
-// This simplifies deserializing elsewhere as we do the checking for presence
-// and string values here for the complete set of serializable keys that the
-// corresponding principal supports.
-//
-// The KeyVal object has the following fields:
-// - valueWasSerialized: is true if the deserialized JSON contained a string
-// value
-// - value: The string that was serialized for this key
-// - key: an SerializableKeys enum value specific to the principal.
-//        For example content principal is an enum of: eURI, eDomain,
-//        eSuffix, eCSP
-//
-//
-//  Given an inner content principal:
-//  {"0": "https://mozilla.com", "2": "^privateBrowsingId=1"}
-//    |                |          |         |
-//    -----------------------------         |
-//         |           |                    |
-//        Key          ----------------------
-//                                |
-//                              Value
-//
-// They Key "0" corresponds to ContentPrincipal::eURI
-// They Key "1" corresponds to ContentPrincipal::eSuffix
-template <typename T>
-static nsTArray<typename T::KeyVal> GetJSONKeys(const Json::Value* aInput) {
-  int size = T::eMax + 1;
-  nsTArray<typename T::KeyVal> fields;
-  for (int i = 0; i != size; i++) {
-    typename T::KeyVal* field = fields.AppendElement();
-    // field->valueWasSerialized returns if the field was found in the
-    // deserialized code. This simplifies the consumers from having to check
-    // length.
-    field->valueWasSerialized = false;
-    field->key = static_cast<typename T::SerializableKeys>(i);
-    const std::string key = std::to_string(field->key);
-    if (aInput->isMember(key)) {
-      const Json::Value& val = (*aInput)[key];
-      if (val.isString()) {
-        field->value.Append(nsDependentCString(val.asCString()));
-        field->valueWasSerialized = true;
+template <typename HandlerTypesT>
+bool ContainerPrincipalJSONHandler<HandlerTypesT>::startObject() {
+  if (mInnerHandler.isSome()) {
+    return CallOnInner([&](auto& aInner) { return aInner.startObject(); });
+  }
+
+  switch (mState) {
+    case State::Init:
+      mState = State::StartObject;
+      break;
+    case State::SystemPrincipal_Key:
+      mState = State::SystemPrincipal_StartObject;
+      break;
+    default:
+      NS_WARNING("Unexpected object value");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
+}
+
+template <typename HandlerTypesT>
+bool ContainerPrincipalJSONHandler<HandlerTypesT>::propertyName(
+    const JS::Latin1Char* name, size_t length) {
+  if (mInnerHandler.isSome()) {
+    return CallOnInner(
+        [&](auto& aInner) { return aInner.propertyName(name, length); });
+  }
+
+  switch (mState) {
+    case State::StartObject: {
+      if (length != 1) {
+        NS_WARNING(
+            nsPrintfCString("Unexpected property name length: %zu", length)
+                .get());
+        mState = State::Error;
+        return false;
       }
+
+      char key = char(name[0]);
+      switch (key) {
+        case BasePrincipal::NullPrincipalKey:
+          mState = State::NullPrincipal_Inner;
+          mInnerHandler.emplace(VariantType<NullPrincipalJSONHandler>());
+          break;
+        case BasePrincipal::ContentPrincipalKey:
+          mState = State::ContentPrincipal_Inner;
+          mInnerHandler.emplace(VariantType<ContentPrincipalJSONHandler>());
+          break;
+        case BasePrincipal::SystemPrincipalKey:
+          mState = State::SystemPrincipal_Key;
+          break;
+        default:
+          if constexpr (CanContainExpandedPrincipal) {
+            if (key == BasePrincipal::ExpandedPrincipalKey) {
+              mState = State::ExpandedPrincipal_Inner;
+              mInnerHandler.emplace(
+                  VariantType<ExpandedPrincipalJSONHandler>());
+              break;
+            }
+          }
+          NS_WARNING(
+              nsPrintfCString("Unexpected property name: '%c'", key).get());
+          mState = State::Error;
+          return false;
+      }
+      break;
+    }
+    default:
+      NS_WARNING("Unexpected property name");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
+}
+
+template <typename HandlerTypesT>
+bool ContainerPrincipalJSONHandler<HandlerTypesT>::endObject() {
+  if (mInnerHandler.isSome()) {
+    return CallOnInner([&](auto& aInner) {
+      if (!aInner.endObject()) {
+        return false;
+      }
+      if (aInner.HasAccepted()) {
+        this->mPrincipal = aInner.mPrincipal.forget();
+        MOZ_ASSERT(this->mPrincipal);
+        mInnerHandler.reset();
+      }
+      return true;
+    });
+  }
+
+  switch (mState) {
+    case State::SystemPrincipal_StartObject:
+      mState = State::SystemPrincipal_EndObject;
+      break;
+    case State::SystemPrincipal_EndObject:
+      this->mPrincipal =
+          BasePrincipal::Cast(nsContentUtils::GetSystemPrincipal());
+      mState = State::EndObject;
+      break;
+    case State::NullPrincipal_Inner:
+      mState = State::EndObject;
+      break;
+    case State::ContentPrincipal_Inner:
+      mState = State::EndObject;
+      break;
+    default:
+      if constexpr (CanContainExpandedPrincipal) {
+        if (mState == State::ExpandedPrincipal_Inner) {
+          mState = State::EndObject;
+          break;
+        }
+      }
+      NS_WARNING("Unexpected end of object");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
+}
+
+template <typename HandlerTypesT>
+bool ContainerPrincipalJSONHandler<HandlerTypesT>::startArray() {
+  if constexpr (CanContainExpandedPrincipal) {
+    if (mInnerHandler.isSome()) {
+      return CallOnInner([&](auto& aInner) { return aInner.startArray(); });
     }
   }
-  return fields;
+
+  NS_WARNING("Unexpected array value");
+  mState = State::Error;
+  return false;
 }
 
+template <typename HandlerTypesT>
+bool ContainerPrincipalJSONHandler<HandlerTypesT>::endArray() {
+  if constexpr (CanContainExpandedPrincipal) {
+    if (mInnerHandler.isSome()) {
+      return CallOnInner([&](auto& aInner) { return aInner.endArray(); });
+    }
+  }
+
+  NS_WARNING("Unexpected array value");
+  mState = State::Error;
+  return false;
+}
+
+template <typename HandlerTypesT>
+bool ContainerPrincipalJSONHandler<HandlerTypesT>::stringValue(
+    const JS::Latin1Char* str, size_t length) {
+  if (mInnerHandler.isSome()) {
+    return CallOnInner(
+        [&](auto& aInner) { return aInner.stringValue(str, length); });
+  }
+
+  NS_WARNING("Unexpected string value");
+  mState = State::Error;
+  return false;
+}
+
+template class ContainerPrincipalJSONHandler<PrincipalJSONHandlerTypes>;
+template class ContainerPrincipalJSONHandler<SubsumedPrincipalJSONHandlerTypes>;
+
 // Takes a JSON string and parses it turning it into a principal of the
 // corresponding type
 //
@@ -266,114 +337,21 @@ static nsTArray<typename T::KeyVal> GetJSONKeys(const Json::Value* aInput) {
 //           SerializableKeys           |
 //                                    Value
 //
-// The string is first deserialized with jsoncpp to get the Json::Value of the
-// object. The inner JSON object is parsed with GetPrincipalObject which returns
-// a KeyVal array of the inner object's fields. PrincipalKind is returned by
-// GetPrincipalObject which is then used to decide which principal
-// implementation of FromProperties to call. The corresponding FromProperties
-// call takes the KeyVal fields and turns it into a principal.
 already_AddRefed<BasePrincipal> BasePrincipal::FromJSON(
     const nsACString& aJSON) {
-  Json::Value root;
-  Json::CharReaderBuilder builder;
-  std::unique_ptr<Json::CharReader> const reader(builder.newCharReader());
-  bool parseSuccess =
-      reader->parse(aJSON.BeginReading(), aJSON.EndReading(), &root, nullptr);
-  if (!parseSuccess) {
+  PrincipalJSONHandler handler;
+
+  if (!JS::ParseJSONWithHandler(
+          reinterpret_cast<const JS::Latin1Char*>(aJSON.BeginReading()),
+          aJSON.Length(), &handler)) {
+    NS_WARNING(
+        nsPrintfCString("Unable to parse: %s", aJSON.BeginReading()).get());
     MOZ_ASSERT(false,
                "Unable to parse string as JSON to deserialize as a principal");
     return nullptr;
   }
 
-  return FromJSON(root);
-}
-
-// Checks if an ExpandedPrincipal is using the legacy format, where
-// sub-principals are Base64 encoded.
-//
-// Given a legacy expanded principal:
-//
-//         *
-// {"2": {"0": "eyIxIjp7IjAiOiJodHRwczovL2EuY29tLyJ9fQ=="}}
-//   |     |                      |
-//   |     ----------           Value
-//   |              |
-// PrincipalKind    |
-//                  |
-//           SerializableKeys
-//
-// The value is a CSV list of Base64 encoded prinipcals. The new format for this
-// principal is:
-//
-//                       Subsumed principals
-//                               |
-//             ------------------------------------
-//         *   |                                  |
-// {"2": {"0": [{"1": {"0": https://mozilla.com"}}]}}
-//   |            |                  |
-//   --------------                Value
-//         |
-//   PrincipalKind
-//
-// It is possible to tell these apart by checking the type of the property noted
-// in both diagrams with an asterisk. In the legacy format the type will be a
-// string and in the new format it will be an array.
-static bool IsLegacyFormat(const Json::Value& aValue) {
-  const auto& specs = std::to_string(ExpandedPrincipal::eSpecs);
-  return aValue.isMember(specs) && aValue[specs].isString();
-}
-
-/* static */
-already_AddRefed<BasePrincipal> BasePrincipal::FromJSON(
-    const Json::Value& aJSON) {
-  int principalKind = -1;
-  const Json::Value* value = GetPrincipalObject(aJSON, principalKind);
-  if (!value) {
-#ifdef DEBUG
-    fprintf(stderr, "Unexpected JSON principal %s\n",
-            aJSON.toStyledString().c_str());
-#endif
-    MOZ_ASSERT(false, "Unexpected JSON to deserialize as a principal");
-
-    return nullptr;
-  }
-  MOZ_ASSERT(principalKind != -1,
-             "PrincipalKind should always be >=0 by this point");
-
-  if (principalKind == eSystemPrincipal) {
-    RefPtr<BasePrincipal> principal =
-        BasePrincipal::Cast(nsContentUtils::GetSystemPrincipal());
-    return principal.forget();
-  }
-
-  if (principalKind == eNullPrincipal) {
-    nsTArray<NullPrincipal::KeyVal> res = GetJSONKeys<NullPrincipal>(value);
-    return NullPrincipal::FromProperties(res);
-  }
-
-  if (principalKind == eContentPrincipal) {
-    nsTArray<ContentPrincipal::KeyVal> res =
-        GetJSONKeys<ContentPrincipal>(value);
-    return ContentPrincipal::FromProperties(res);
-  }
-
-  if (principalKind == eExpandedPrincipal) {
-    // Check if expanded principals is stored in the new or the old format. See
-    // comment for `IsLegacyFormat`.
-    if (IsLegacyFormat(*value)) {
-      nsTArray<ExpandedPrincipal::KeyVal> res =
-          GetJSONKeys<ExpandedPrincipal>(value);
-      return ExpandedPrincipal::FromProperties(res);
-    }
-
-    return ExpandedPrincipal::FromProperties(*value);
-  }
-
-  MOZ_RELEASE_ASSERT(false, "Unexpected enum to deserialize as a principal");
-}
-
-nsresult BasePrincipal::PopulateJSONObject(Json::Value& aObject) {
-  return NS_OK;
+  return handler.Get();
 }
 
 // Returns a JSON representation of the principal.
@@ -383,34 +361,42 @@ nsresult BasePrincipal::ToJSON(nsACString& aJSON) {
   MOZ_ASSERT(aJSON.IsEmpty(), "ToJSON only supports an empty result input");
   aJSON.Truncate();
 
-  Json::Value root = Json::objectValue;
-  nsresult rv = ToJSON(root);
-  NS_ENSURE_SUCCESS(rv, rv);
+  // NOTE: JSONWriter emits raw UTF-8 code units for non-ASCII range.
+  JSONStringRefWriteFunc func(aJSON);
+  JSONWriter writer(func, JSONWriter::CollectionStyle::SingleLineStyle);
 
-  static StaticAutoPtr<Json::StreamWriterBuilder> sJSONBuilderForPrincipals;
-  if (!sJSONBuilderForPrincipals) {
-    sJSONBuilderForPrincipals = new Json::StreamWriterBuilder();
-    (*sJSONBuilderForPrincipals)["indentation"] = "";
-    (*sJSONBuilderForPrincipals)["emitUTF8"] = true;
-    ClearOnShutdown(&sJSONBuilderForPrincipals);
-  }
-  std::string result = Json::writeString(*sJSONBuilderForPrincipals, root);
-  aJSON.Append(result);
-  if (aJSON.Length() == 0) {
-    MOZ_ASSERT(false, "JSON writer failed to output a principal serialization");
-    return NS_ERROR_UNEXPECTED;
-  }
+  nsresult rv = ToJSON(writer);
+  NS_ENSURE_SUCCESS(rv, rv);
 
   return NS_OK;
 }
 
-nsresult BasePrincipal::ToJSON(Json::Value& aObject) {
+nsresult BasePrincipal::ToJSON(JSONWriter& aWriter) {
   static_assert(eKindMax < ArrayLength(JSONEnumKeyStrings));
-  nsresult rv = PopulateJSONObject(
-      (aObject[Json::StaticString(JSONEnumKeyStrings[Kind()])] =
-           Json::objectValue));
+
+  aWriter.Start(JSONWriter::CollectionStyle::SingleLineStyle);
+
+  nsresult rv = WriteJSONProperties(aWriter);
   NS_ENSURE_SUCCESS(rv, rv);
 
+  aWriter.End();
+
+  return NS_OK;
+}
+
+nsresult BasePrincipal::WriteJSONProperties(JSONWriter& aWriter) {
+  aWriter.StartObjectProperty(JSONEnumKeyStrings[Kind()],
+                              JSONWriter::CollectionStyle::SingleLineStyle);
+
+  nsresult rv = WriteJSONInnerProperties(aWriter);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  aWriter.EndObject();
+
+  return NS_OK;
+}
+
+nsresult BasePrincipal::WriteJSONInnerProperties(JSONWriter& aWriter) {
   return NS_OK;
 }
 
@@ -1618,10 +1604,10 @@ BasePrincipal::Deserializer::Write(nsIObjectOutputStream* aStream) {
 }
 
 /* static */
-void BasePrincipal::SetJSONValue(Json::Value& aObject, const char* aKey,
-                                 const nsCString& aValue) {
-  aObject[Json::StaticString(aKey)] =
-      Json::Value(aValue.BeginReading(), aValue.EndReading());
+void BasePrincipal::WriteJSONProperty(JSONWriter& aWriter,
+                                      const Span<const char>& aKey,
+                                      const nsCString& aValue) {
+  aWriter.StringProperty(aKey, aValue);
 }
 
 }  // namespace mozilla

caps/BasePrincipal.h

@@ -27,12 +27,11 @@ class nsIChannel;
 class nsIReferrerInfo;
 class nsISupports;
 class nsIURI;
-namespace Json {
-class Value;
-}
 
 namespace mozilla {
 
+class JSONWriter;
+
 namespace dom {
 enum class ReferrerPolicy : uint8_t;
 }
@@ -91,6 +90,15 @@ class BasePrincipal : public nsJSPrincipals {
     eKindMax = eSystemPrincipal
   };
 
+  static constexpr char NullPrincipalKey = '0';
+  static_assert(eNullPrincipal == 0);
+  static constexpr char ContentPrincipalKey = '1';
+  static_assert(eContentPrincipal == 1);
+  static constexpr char ExpandedPrincipalKey = '2';
+  static_assert(eExpandedPrincipal == 2);
+  static constexpr char SystemPrincipalKey = '3';
+  static_assert(eSystemPrincipal == 3);
+
   template <typename T>
   bool Is() const {
     return mKind == T::Kind();
@@ -189,13 +197,14 @@ class BasePrincipal : public nsJSPrincipals {
   NS_IMETHOD GetPrecursorPrincipal(nsIPrincipal** aPrecursor) override;
 
   nsresult ToJSON(nsACString& aJSON);
-  nsresult ToJSON(Json::Value& aObject);
+  nsresult ToJSON(JSONWriter& aWriter);
+  nsresult WriteJSONProperties(JSONWriter& aWriter);
 
   static already_AddRefed<BasePrincipal> FromJSON(const nsACString& aJSON);
-  static already_AddRefed<BasePrincipal> FromJSON(const Json::Value& aJSON);
-  // Method populates a passed Json::Value with serializable fields
-  // which represent all of the fields to deserialize the principal
-  virtual nsresult PopulateJSONObject(Json::Value& aObject);
+
+  // Method to write serializable fields which represent all of the fields to
+  // deserialize the principal.
+  virtual nsresult WriteJSONInnerProperties(JSONWriter& aWriter);
 
   virtual bool AddonHasPermission(const nsAtom* aPerm);
 
@@ -344,20 +353,26 @@ class BasePrincipal : public nsJSPrincipals {
   };
 
  private:
-  static const char* JSONEnumKeyStrings[4];
+  static constexpr Span<const char> JSONEnumKeyStrings[4] = {
+      MakeStringSpan("0"),
+      MakeStringSpan("1"),
+      MakeStringSpan("2"),
+      MakeStringSpan("3"),
+  };
 
-  static void SetJSONValue(Json::Value& aObject, const char* aKey,
-                           const nsCString& aValue);
+  static void WriteJSONProperty(JSONWriter& aWriter,
+                                const Span<const char>& aKey,
+                                const nsCString& aValue);
 
  protected:
   template <size_t EnumValue>
-  static inline constexpr const char* JSONEnumKeyString() {
+  static inline constexpr const Span<const char>& JSONEnumKeyString() {
     static_assert(EnumValue < ArrayLength(JSONEnumKeyStrings));
     return JSONEnumKeyStrings[EnumValue];
   }
   template <size_t EnumValue>
-  static void SetJSONValue(Json::Value& aObject, const nsCString& aValue) {
-    SetJSONValue(aObject, JSONEnumKeyString<EnumValue>(), aValue);
+  static void WriteJSONProperty(JSONWriter& aWriter, const nsCString& aValue) {
+    WriteJSONProperty(aWriter, JSONEnumKeyString<EnumValue>(), aValue);
   }
 
  private:

caps/ContentPrincipal.cpp

@@ -38,7 +38,9 @@
 #include "mozilla/HashFunctions.h"
 
 #include "nsSerializationHelper.h"
-#include "json/json.h"
+
+#include "js/JSON.h"
+#include "ContentPrincipalJSONHandler.h"
 
 using namespace mozilla;
 
@@ -605,14 +607,14 @@ ContentPrincipal::Deserializer::Read(nsIObjectInputStream* aStream) {
   return NS_OK;
 }
 
-nsresult ContentPrincipal::PopulateJSONObject(Json::Value& aObject) {
+nsresult ContentPrincipal::WriteJSONInnerProperties(JSONWriter& aWriter) {
   nsAutoCString principalURI;
   nsresult rv = mURI->GetSpec(principalURI);
   NS_ENSURE_SUCCESS(rv, rv);
 
-  // We turn each int enum field into a JSON string key of the object
-  // aObject is the inner JSON object that has stringified enum keys
-  // An example aObject might be:
+  // We turn each int enum field into a JSON string key of the object, aWriter
+  // is set up to be inside of the inner object that has stringified enum keys
+  // An example inner object might be:
   //
   // eURI                   eSuffix
   //    |                           |
@@ -623,7 +625,7 @@ nsresult ContentPrincipal::PopulateJSONObject(Json::Value& aObject) {
   //        Key          ----------------------
   //                                |
   //                              Value
-  SetJSONValue<eURI>(aObject, principalURI);
+  WriteJSONProperty<eURI>(aWriter, principalURI);
 
   if (GetHasExplicitDomain()) {
     nsAutoCString domainStr;
@@ -632,78 +634,159 @@ nsresult ContentPrincipal::PopulateJSONObject(Json::Value& aObject) {
       rv = mDomain->GetSpec(domainStr);
       NS_ENSURE_SUCCESS(rv, rv);
     }
-    SetJSONValue<eDomain>(aObject, domainStr);
+    WriteJSONProperty<eDomain>(aWriter, domainStr);
   }
 
   nsAutoCString suffix;
   OriginAttributesRef().CreateSuffix(suffix);
   if (suffix.Length() > 0) {
-    SetJSONValue<eSuffix>(aObject, suffix);
+    WriteJSONProperty<eSuffix>(aWriter, suffix);
   }
 
   return NS_OK;
 }
 
-already_AddRefed<BasePrincipal> ContentPrincipal::FromProperties(
-    nsTArray<ContentPrincipal::KeyVal>& aFields) {
-  MOZ_ASSERT(aFields.Length() == eMax + 1, "Must have all the keys");
-  nsresult rv;
-  nsCOMPtr<nsIURI> principalURI;
-  nsCOMPtr<nsIURI> domain;
-  nsCOMPtr<nsIContentSecurityPolicy> csp;
-  OriginAttributes attrs;
-
-  // The odd structure here is to make the code to not compile
-  // if all the switch enum cases haven't been codified
-  for (const auto& field : aFields) {
-    switch (field.key) {
-      case ContentPrincipal::eURI:
-        if (!field.valueWasSerialized) {
-          MOZ_ASSERT(
-              false,
-              "Content principals require a principal URI in serialized JSON");
-          return nullptr;
-        }
-        rv = NS_NewURI(getter_AddRefs(principalURI), field.value.get());
-        NS_ENSURE_SUCCESS(rv, nullptr);
-
-        {
-          // Enforce re-parsing about: URIs so that if they change, we
-          // continue to use their new principals correctly.
-          if (principalURI->SchemeIs("about")) {
-            nsAutoCString spec;
-            principalURI->GetSpec(spec);
-            if (NS_FAILED(NS_NewURI(getter_AddRefs(principalURI), spec))) {
-              return nullptr;
-            }
-          }
-        }
-        break;
-      case ContentPrincipal::eDomain:
-        if (field.valueWasSerialized) {
-          rv = NS_NewURI(getter_AddRefs(domain), field.value.get());
-          NS_ENSURE_SUCCESS(rv, nullptr);
-        }
-        break;
-      case ContentPrincipal::eSuffix:
-        if (field.valueWasSerialized) {
-          bool ok = attrs.PopulateFromSuffix(field.value);
-          if (!ok) {
-            return nullptr;
-          }
-        }
-        break;
-    }
-  }
-  nsAutoCString originNoSuffix;
-  rv = ContentPrincipal::GenerateOriginNoSuffixFromURI(principalURI,
-                                                       originNoSuffix);
-  if (NS_FAILED(rv)) {
-    return nullptr;
+bool ContentPrincipalJSONHandler::startObject() {
+  switch (mState) {
+    case State::Init:
+      mState = State::StartObject;
+      break;
+    default:
+      NS_WARNING("Unexpected object value");
+      mState = State::Error;
+      return false;
   }
 
-  RefPtr<ContentPrincipal> principal =
-      new ContentPrincipal(principalURI, attrs, originNoSuffix, domain);
-
-  return principal.forget();
+  return true;
+}
+
+bool ContentPrincipalJSONHandler::propertyName(const JS::Latin1Char* name,
+                                               size_t length) {
+  switch (mState) {
+    case State::StartObject:
+    case State::AfterPropertyValue: {
+      if (length != 1) {
+        NS_WARNING(
+            nsPrintfCString("Unexpected property name length: %zu", length)
+                .get());
+        mState = State::Error;
+        return false;
+      }
+
+      char key = char(name[0]);
+      switch (key) {
+        case ContentPrincipal::URIKey:
+          mState = State::URIKey;
+          break;
+        case ContentPrincipal::DomainKey:
+          mState = State::DomainKey;
+          break;
+        case ContentPrincipal::SuffixKey:
+          mState = State::SuffixKey;
+          break;
+        default:
+          NS_WARNING(
+              nsPrintfCString("Unexpected property name: '%c'", key).get());
+          mState = State::Error;
+          return false;
+      }
+      break;
+    }
+    default:
+      NS_WARNING("Unexpected property name");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
+}
+
+bool ContentPrincipalJSONHandler::endObject() {
+  switch (mState) {
+    case State::AfterPropertyValue: {
+      MOZ_ASSERT(mPrincipalURI);
+      // NOTE: mDomain is optional.
+
+      nsAutoCString originNoSuffix;
+      nsresult rv = ContentPrincipal::GenerateOriginNoSuffixFromURI(
+          mPrincipalURI, originNoSuffix);
+      if (NS_FAILED(rv)) {
+        mState = State::Error;
+        return false;
+      }
+
+      mPrincipal =
+          new ContentPrincipal(mPrincipalURI, mAttrs, originNoSuffix, mDomain);
+      MOZ_ASSERT(mPrincipal);
+
+      mState = State::EndObject;
+      break;
+    }
+    default:
+      NS_WARNING("Unexpected end of object");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
+}
+
+bool ContentPrincipalJSONHandler::stringValue(const JS::Latin1Char* str,
+                                              size_t length) {
+  switch (mState) {
+    case State::URIKey: {
+      nsDependentCSubstring spec(reinterpret_cast<const char*>(str), length);
+
+      nsresult rv = NS_NewURI(getter_AddRefs(mPrincipalURI), spec);
+      if (NS_FAILED(rv)) {
+        mState = State::Error;
+        return false;
+      }
+
+      {
+        // Enforce re-parsing about: URIs so that if they change, we
+        // continue to use their new principals correctly.
+        if (mPrincipalURI->SchemeIs("about")) {
+          nsAutoCString spec;
+          mPrincipalURI->GetSpec(spec);
+          rv = NS_NewURI(getter_AddRefs(mPrincipalURI), spec);
+          if (NS_FAILED(rv)) {
+            mState = State::Error;
+            return false;
+          }
+        }
+      }
+
+      mState = State::AfterPropertyValue;
+      break;
+    }
+    case State::DomainKey: {
+      nsDependentCSubstring spec(reinterpret_cast<const char*>(str), length);
+
+      nsresult rv = NS_NewURI(getter_AddRefs(mDomain), spec);
+      if (NS_FAILED(rv)) {
+        mState = State::Error;
+        return false;
+      }
+
+      mState = State::AfterPropertyValue;
+      break;
+    }
+    case State::SuffixKey: {
+      nsDependentCSubstring attrs(reinterpret_cast<const char*>(str), length);
+      if (!mAttrs.PopulateFromSuffix(attrs)) {
+        mState = State::Error;
+        return false;
+      }
+
+      mState = State::AfterPropertyValue;
+      break;
+    }
+    default:
+      NS_WARNING("Unexpected string value");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
 }

caps/ContentPrincipal.h

@@ -15,12 +15,10 @@
 #include "mozilla/Mutex.h"
 #include "mozilla/extensions/WebExtensionPolicy.h"
 
-namespace Json {
-class Value;
-}
-
 namespace mozilla {
 
+class JSONWriter;
+
 class ContentPrincipal final : public BasePrincipal {
  public:
   NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override;
@@ -49,7 +47,8 @@ class ContentPrincipal final : public BasePrincipal {
 
   RefPtr<extensions::WebExtensionPolicyCore> AddonPolicyCore();
 
-  virtual nsresult PopulateJSONObject(Json::Value& aObject) override;
+  virtual nsresult WriteJSONInnerProperties(JSONWriter& aWriter) override;
+
   // Serializable keys are the valid enum fields the serialization supports
   enum SerializableKeys : uint8_t {
     eURI = 0,
@@ -57,10 +56,13 @@ class ContentPrincipal final : public BasePrincipal {
     eSuffix,
     eMax = eSuffix
   };
-  typedef mozilla::BasePrincipal::KeyValT<SerializableKeys> KeyVal;
 
-  static already_AddRefed<BasePrincipal> FromProperties(
-      nsTArray<ContentPrincipal::KeyVal>& aFields);
+  static constexpr char URIKey = '0';
+  static_assert(eURI == 0);
+  static constexpr char DomainKey = '1';
+  static_assert(eDomain == 1);
+  static constexpr char SuffixKey = '2';
+  static_assert(eSuffix == 2);
 
   class Deserializer : public BasePrincipal::Deserializer {
    public:

caps/ContentPrincipalJSONHandler.h

@@ -0,0 +1,94 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_ContentPrincipalJSONHandler_h
+#define mozilla_ContentPrincipalJSONHandler_h
+
+#include <stddef.h>  // size_t
+#include <stdint.h>  // uint32_t
+
+#include "js/TypeDecls.h"  // JS::Latin1Char
+
+#include "mozilla/AlreadyAddRefed.h"  // already_AddRefed
+#include "mozilla/RefPtr.h"           // RefPtr
+
+#include "nsCOMPtr.h"  // nsCOMPtr
+#include "nsDebug.h"   // NS_WARNING
+#include "nsIURI.h"    // nsIURI
+
+#include "ContentPrincipal.h"
+#include "OriginAttributes.h"
+#include "SharedJSONHandler.h"
+
+namespace mozilla {
+
+// JSON parse handler for an inner object for ContentPrincipal.
+// Used by PrincipalJSONHandler or SubsumedPrincipalJSONHandler.
+class ContentPrincipalJSONHandler : public PrincipalJSONHandlerShared {
+  enum class State {
+    Init,
+
+    // After the inner object's '{'.
+    StartObject,
+
+    // After the property key for eURI.
+    URIKey,
+
+    // After the property key for eDomain.
+    DomainKey,
+
+    // After the property key for eSuffix.
+    SuffixKey,
+
+    // After the property value for eURI, eDomain, or eSuffix.
+    AfterPropertyValue,
+
+    // After the inner object's '}'.
+    EndObject,
+
+    Error,
+  };
+
+ public:
+  ContentPrincipalJSONHandler() = default;
+  virtual ~ContentPrincipalJSONHandler() = default;
+
+  virtual bool startObject() override;
+
+  using PrincipalJSONHandlerShared::propertyName;
+  virtual bool propertyName(const JS::Latin1Char* name, size_t length) override;
+
+  virtual bool endObject() override;
+
+  virtual bool startArray() override {
+    NS_WARNING("Unexpected array value");
+    mState = State::Error;
+    return false;
+  }
+  virtual bool endArray() override {
+    NS_WARNING("Unexpected array value");
+    mState = State::Error;
+    return false;
+  }
+
+  using PrincipalJSONHandlerShared::stringValue;
+  virtual bool stringValue(const JS::Latin1Char* str, size_t length) override;
+
+  bool HasAccepted() const { return mState == State::EndObject; }
+
+ protected:
+  virtual void SetErrorState() override { mState = State::Error; }
+
+ private:
+  State mState = State::Init;
+
+  nsCOMPtr<nsIURI> mPrincipalURI;
+  nsCOMPtr<nsIURI> mDomain;
+  OriginAttributes mAttrs;
+};
+
+}  // namespace mozilla
+
+#endif  // mozilla_ContentPrincipalJSONHandler_h

caps/ExpandedPrincipal.cpp

@@ -10,7 +10,11 @@
 #include "nsReadableUtils.h"
 #include "mozilla/Base64.h"
 #include "mozilla/extensions/WebExtensionPolicy.h"
-#include "json/json.h"
+#include "mozilla/JSONWriter.h"
+
+#include "js/JSON.h"
+#include "ExpandedPrincipalJSONHandler.h"
+#include "SubsumedPrincipalJSONHandler.h"
 
 using namespace mozilla;
 
@@ -262,121 +266,211 @@ nsresult ExpandedPrincipal::GetSiteIdentifier(SiteIdentifier& aSite) {
   return NS_OK;
 }
 
-nsresult ExpandedPrincipal::PopulateJSONObject(Json::Value& aObject) {
-  Json::Value& principalList =
-      aObject[Json::StaticString(JSONEnumKeyString<eSpecs>())] =
-          Json::arrayValue;
+nsresult ExpandedPrincipal::WriteJSONInnerProperties(JSONWriter& aWriter) {
+  aWriter.StartArrayProperty(JSONEnumKeyString<eSpecs>(),
+                             JSONWriter::CollectionStyle::SingleLineStyle);
+
   for (const auto& principal : mPrincipals) {
-    Json::Value object = Json::objectValue;
-    nsresult rv = BasePrincipal::Cast(principal)->ToJSON(object);
+    aWriter.StartObjectElement(JSONWriter::CollectionStyle::SingleLineStyle);
+
+    nsresult rv = BasePrincipal::Cast(principal)->WriteJSONProperties(aWriter);
     NS_ENSURE_SUCCESS(rv, rv);
 
-    principalList.append(std::move(object));
+    aWriter.EndObject();
   }
 
+  aWriter.EndArray();
+
   nsAutoCString suffix;
   OriginAttributesRef().CreateSuffix(suffix);
   if (suffix.Length() > 0) {
-    SetJSONValue<eSuffix>(aObject, suffix);
+    WriteJSONProperty<eSuffix>(aWriter, suffix);
   }
 
   return NS_OK;
 }
 
-already_AddRefed<BasePrincipal> ExpandedPrincipal::FromProperties(
-    nsTArray<ExpandedPrincipal::KeyVal>& aFields) {
-  MOZ_ASSERT(aFields.Length() == eMax + 1, "Must have all the keys");
-  nsTArray<nsCOMPtr<nsIPrincipal>> allowList;
-  OriginAttributes attrs;
-  // The odd structure here is to make the code to not compile
-  // if all the switch enum cases haven't been codified
-
-  for (const auto& field : aFields) {
-    switch (field.key) {
-      case ExpandedPrincipal::eSpecs:
-        if (!field.valueWasSerialized) {
-          MOZ_ASSERT(false,
-                     "Expanded principals require specs in serialized JSON");
-          return nullptr;
-        }
-        for (const nsACString& each : field.value.Split(',')) {
-          nsAutoCString result;
-          nsresult rv;
-          rv = Base64Decode(each, result);
-          MOZ_ASSERT(NS_SUCCEEDED(rv), "failed to decode");
-
-          NS_ENSURE_SUCCESS(rv, nullptr);
-          nsCOMPtr<nsIPrincipal> principal = BasePrincipal::FromJSON(result);
-          allowList.AppendElement(principal);
-        }
-        break;
-      case ExpandedPrincipal::eSuffix:
-        if (field.valueWasSerialized) {
-          bool ok = attrs.PopulateFromSuffix(field.value);
-          if (!ok) {
-            return nullptr;
-          }
-        }
-        break;
-    }
+bool ExpandedPrincipalJSONHandler::ProcessSubsumedResult(bool aResult) {
+  if (!aResult) {
+    NS_WARNING("Failed to parse subsumed principal");
+    mState = State::Error;
+    return false;
   }
-
-  if (allowList.Length() == 0) {
-    return nullptr;
-  }
-
-  RefPtr<ExpandedPrincipal> expandedPrincipal =
-      ExpandedPrincipal::Create(allowList, attrs);
-
-  return expandedPrincipal.forget();
+  return true;
 }
 
-/* static */
-already_AddRefed<BasePrincipal> ExpandedPrincipal::FromProperties(
-    const Json::Value& aJSON) {
-  MOZ_ASSERT(aJSON.size() <= eMax + 1, "Must have at most, all the properties");
-  const std::string specs = std::to_string(eSpecs);
-  const std::string suffix = std::to_string(eSuffix);
-  MOZ_ASSERT(aJSON.isMember(specs), "The eSpecs member is required");
-  MOZ_ASSERT(aJSON.size() == 1 || aJSON.isMember(suffix),
-             "eSuffix is optional");
-
-  const auto* specsValue =
-      aJSON.find(specs.c_str(), specs.c_str() + specs.length());
-  if (!specsValue) {
-    MOZ_ASSERT(false, "Expanded principals require specs in serialized JSON");
-    return nullptr;
+bool ExpandedPrincipalJSONHandler::startObject() {
+  if (mSubsumedHandler.isSome()) {
+    return ProcessSubsumedResult(mSubsumedHandler->startObject());
   }
 
-  nsTArray<nsCOMPtr<nsIPrincipal>> allowList;
-  for (const auto& principalJSON : *specsValue) {
-    if (nsCOMPtr<nsIPrincipal> principal =
-            BasePrincipal::FromJSON(principalJSON)) {
-      allowList.AppendElement(principal);
+  switch (mState) {
+    case State::Init:
+      mState = State::StartObject;
+      break;
+    case State::StartArray:
+      mState = State::SubsumedPrincipal;
+      [[fallthrough]];
+    case State::SubsumedPrincipal:
+      mSubsumedHandler.emplace();
+
+      return ProcessSubsumedResult(mSubsumedHandler->startObject());
+    default:
+      NS_WARNING("Unexpected object value");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
+}
+
+bool ExpandedPrincipalJSONHandler::propertyName(const JS::Latin1Char* name,
+                                                size_t length) {
+  if (mSubsumedHandler.isSome()) {
+    return ProcessSubsumedResult(mSubsumedHandler->propertyName(name, length));
+  }
+
+  switch (mState) {
+    case State::StartObject:
+    case State::AfterPropertyValue: {
+      if (length != 1) {
+        NS_WARNING(
+            nsPrintfCString("Unexpected property name length: %zu", length)
+                .get());
+        mState = State::Error;
+        return false;
+      }
+
+      char key = char(name[0]);
+      switch (key) {
+        case ExpandedPrincipal::SpecsKey:
+          mState = State::SpecsKey;
+          break;
+        case ExpandedPrincipal::SuffixKey:
+          mState = State::SuffixKey;
+          break;
+        default:
+          NS_WARNING(
+              nsPrintfCString("Unexpected property name: '%c'", key).get());
+          mState = State::Error;
+          return false;
+      }
+      break;
     }
+    default:
+      NS_WARNING("Unexpected property name");
+      mState = State::Error;
+      return false;
   }
 
-  if (allowList.Length() == 0) {
-    return nullptr;
-  }
+  return true;
+}
 
-  OriginAttributes attrs;
-  if (aJSON.isMember(suffix)) {
-    const auto& value = aJSON[suffix];
-    if (!value.isString()) {
-      return nullptr;
+bool ExpandedPrincipalJSONHandler::endObject() {
+  if (mSubsumedHandler.isSome()) {
+    if (!ProcessSubsumedResult(mSubsumedHandler->endObject())) {
+      return false;
     }
-
-    bool ok = attrs.PopulateFromSuffix(nsDependentCString(value.asCString()));
-    if (!ok) {
-      return nullptr;
+    if (mSubsumedHandler->HasAccepted()) {
+      nsCOMPtr<nsIPrincipal> principal = mSubsumedHandler->mPrincipal.forget();
+      mSubsumedHandler.reset();
+      mAllowList.AppendElement(principal);
     }
+    return true;
   }
 
-  RefPtr<ExpandedPrincipal> expandedPrincipal =
-      ExpandedPrincipal::Create(allowList, attrs);
+  switch (mState) {
+    case State::AfterPropertyValue:
+      mPrincipal = ExpandedPrincipal::Create(mAllowList, mAttrs);
+      MOZ_ASSERT(mPrincipal);
 
-  return expandedPrincipal.forget();
+      mState = State::EndObject;
+      break;
+    default:
+      NS_WARNING("Unexpected end of object");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
+}
+
+bool ExpandedPrincipalJSONHandler::startArray() {
+  switch (mState) {
+    case State::SpecsKey:
+      mState = State::StartArray;
+      break;
+    default:
+      NS_WARNING("Unexpected array value");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
+}
+
+bool ExpandedPrincipalJSONHandler::endArray() {
+  switch (mState) {
+    case State::SubsumedPrincipal: {
+      mState = State::AfterPropertyValue;
+      break;
+    }
+    default:
+      NS_WARNING("Unexpected end of array");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
+}
+
+bool ExpandedPrincipalJSONHandler::stringValue(const JS::Latin1Char* str,
+                                               size_t length) {
+  if (mSubsumedHandler.isSome()) {
+    return ProcessSubsumedResult(mSubsumedHandler->stringValue(str, length));
+  }
+
+  switch (mState) {
+    case State::SpecsKey: {
+      nsDependentCSubstring specs(reinterpret_cast<const char*>(str), length);
+
+      for (const nsACString& each : specs.Split(',')) {
+        nsAutoCString result;
+        nsresult rv = Base64Decode(each, result);
+        MOZ_ASSERT(NS_SUCCEEDED(rv), "failed to decode");
+        if (NS_FAILED(rv)) {
+          mState = State::Error;
+          return false;
+        }
+
+        nsCOMPtr<nsIPrincipal> principal = BasePrincipal::FromJSON(result);
+        if (!principal) {
+          mState = State::Error;
+          return false;
+        }
+        mAllowList.AppendElement(principal);
+      }
+
+      mState = State::AfterPropertyValue;
+      break;
+    }
+    case State::SuffixKey: {
+      nsDependentCSubstring attrs(reinterpret_cast<const char*>(str), length);
+      if (!mAttrs.PopulateFromSuffix(attrs)) {
+        mState = State::Error;
+        return false;
+      }
+
+      mState = State::AfterPropertyValue;
+      break;
+    }
+    default:
+      NS_WARNING("Unexpected string value");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
 }
 
 NS_IMETHODIMP

caps/ExpandedPrincipal.h

@@ -15,9 +15,9 @@
 
 class nsIContentSecurityPolicy;
 
-namespace Json {
-class Value;
-}
+namespace mozilla {
+class JSONWriter;
+}  // namespace mozilla
 
 class ExpandedPrincipal : public nsIExpandedPrincipal,
                           public mozilla::BasePrincipal {
@@ -57,20 +57,16 @@ class ExpandedPrincipal : public nsIExpandedPrincipal,
 
   nsresult GetSiteIdentifier(mozilla::SiteIdentifier& aSite) override;
 
-  virtual nsresult PopulateJSONObject(Json::Value& aObject) override;
+  virtual nsresult WriteJSONInnerProperties(
+      mozilla::JSONWriter& aWriter) override;
+
   // Serializable keys are the valid enum fields the serialization supports
   enum SerializableKeys : uint8_t { eSpecs = 0, eSuffix, eMax = eSuffix };
-  typedef mozilla::BasePrincipal::KeyValT<SerializableKeys> KeyVal;
 
-  // This is the legacy serializer for expanded principals. See note for
-  // `IsLegacyFormat` in BasePrincipal.cpp.
-  static already_AddRefed<BasePrincipal> FromProperties(
-      nsTArray<ExpandedPrincipal::KeyVal>& aFields);
-
-  // This is the new serializer for expanded principals. See note for
-  // `IsLegacyFormat` in BasePrincipal.cpp.
-  static already_AddRefed<BasePrincipal> FromProperties(
-      const Json::Value& aJSON);
+  static constexpr char SpecsKey = '0';
+  static_assert(eSpecs == 0);
+  static constexpr char SuffixKey = '1';
+  static_assert(eSuffix == 1);
 
   class Deserializer : public BasePrincipal::Deserializer {
    public:

caps/ExpandedPrincipalJSONHandler.h

@@ -0,0 +1,130 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_ExpandedPrincipalJSONHandler_h
+#define mozilla_ExpandedPrincipalJSONHandler_h
+
+#include <stddef.h>  // size_t
+#include <stdint.h>  // uint32_t
+
+#include "js/TypeDecls.h"  // JS::Latin1Char
+
+#include "mozilla/AlreadyAddRefed.h"  // already_AddRefed
+#include "mozilla/Maybe.h"            // Maybe
+#include "mozilla/RefPtr.h"           // RefPtr
+
+#include "nsCOMPtr.h"      // nsCOMPtr
+#include "nsDebug.h"       // NS_WARNING
+#include "nsIPrincipal.h"  // nsIPrincipal
+#include "nsTArray.h"      // nsTArray
+
+#include "OriginAttributes.h"
+#include "ExpandedPrincipal.h"
+#include "SubsumedPrincipalJSONHandler.h"
+#include "SharedJSONHandler.h"
+
+namespace mozilla {
+
+// JSON parse handler for an inner object for ExpandedPrincipal.
+//
+// # Legacy format
+//
+//                           inner object
+//                                |
+//       -------------------------------------------------
+//       |                                               |
+// {"2": {"0": "eyIxIjp7IjAiOiJodHRwczovL2EuY29tLyJ9fQ=="}}
+//   |     |                      |
+//   |     ----------           Value
+//   |              |
+// PrincipalKind    |
+//                  |
+//           SerializableKeys
+//
+// The value is a CSV list of Base64 encoded prinipcals.
+//
+// # New format
+//
+//                           inner object
+//                                |
+//       -------------------------------------------
+//       |                                         |
+//       |               Subsumed principals       |
+//       |                       |                 |
+//       |     ------------------------------------|
+//       |     |                                  ||
+// {"2": {"0": [{"1": {"0": https://mozilla.com"}}]}}
+//   |            |                  |
+//   --------------                Value
+//         |
+//   PrincipalKind
+//
+// Used by PrincipalJSONHandler.
+class ExpandedPrincipalJSONHandler : public PrincipalJSONHandlerShared {
+  enum class State {
+    Init,
+
+    // After the inner object's '{'.
+    StartObject,
+
+    // After the property key for eSpecs.
+    SpecsKey,
+
+    // After the property key for eSuffix.
+    SuffixKey,
+
+    // After the subsumed principals array's '['.
+    StartArray,
+
+    // Subsumed principals array's item.
+    // Delegates to mSubsumedHandler until the subsumed object's '}'.
+    SubsumedPrincipal,
+
+    // After the property value for eSpecs or eSuffix,
+    // including after the subsumed principals array's ']'.
+    AfterPropertyValue,
+
+    // After the inner object's '}'.
+    EndObject,
+
+    Error,
+  };
+
+ public:
+  ExpandedPrincipalJSONHandler() = default;
+  virtual ~ExpandedPrincipalJSONHandler() = default;
+
+  virtual bool startObject() override;
+
+  using PrincipalJSONHandlerShared::propertyName;
+  virtual bool propertyName(const JS::Latin1Char* name, size_t length) override;
+
+  virtual bool endObject() override;
+
+  virtual bool startArray() override;
+  virtual bool endArray() override;
+
+  using PrincipalJSONHandlerShared::stringValue;
+  virtual bool stringValue(const JS::Latin1Char* str, size_t length) override;
+
+  bool HasAccepted() const { return mState == State::EndObject; }
+
+ protected:
+  virtual void SetErrorState() override { mState = State::Error; }
+
+ private:
+  bool ProcessSubsumedResult(bool aResult);
+
+ private:
+  State mState = State::Init;
+
+  nsTArray<nsCOMPtr<nsIPrincipal>> mAllowList;
+  OriginAttributes mAttrs;
+  Maybe<SubsumedPrincipalJSONHandler> mSubsumedHandler;
+};
+
+}  // namespace mozilla
+
+#endif  // mozilla_ExpandedPrincipalJSONHandler_h

caps/NullPrincipal.cpp

@@ -27,7 +27,8 @@
 #include "pratom.h"
 #include "nsIObjectInputStream.h"
 
-#include "json/json.h"
+#include "js/JSON.h"
+#include "NullPrincipalJSONHandler.h"
 
 using namespace mozilla;
 
@@ -236,58 +237,21 @@ NullPrincipal::Deserializer::Read(nsIObjectInputStream* aStream) {
   return NS_OK;
 }
 
-nsresult NullPrincipal::PopulateJSONObject(Json::Value& aObject) {
+nsresult NullPrincipal::WriteJSONInnerProperties(JSONWriter& aWriter) {
   nsAutoCString principalURI;
   nsresult rv = mURI->GetSpec(principalURI);
   NS_ENSURE_SUCCESS(rv, rv);
-  SetJSONValue<eSpec>(aObject, principalURI);
+  WriteJSONProperty<eSpec>(aWriter, principalURI);
 
   nsAutoCString suffix;
   OriginAttributesRef().CreateSuffix(suffix);
   if (suffix.Length() > 0) {
-    SetJSONValue<eSuffix>(aObject, suffix);
+    WriteJSONProperty<eSuffix>(aWriter, suffix);
   }
 
   return NS_OK;
 }
 
-already_AddRefed<BasePrincipal> NullPrincipal::FromProperties(
-    nsTArray<NullPrincipal::KeyVal>& aFields) {
-  MOZ_ASSERT(aFields.Length() == eMax + 1, "Must have all the keys");
-  nsresult rv;
-  nsCOMPtr<nsIURI> uri;
-  OriginAttributes attrs;
-
-  // The odd structure here is to make the code to not compile
-  // if all the switch enum cases haven't been codified
-  for (const auto& field : aFields) {
-    switch (field.key) {
-      case NullPrincipal::eSpec:
-        if (!field.valueWasSerialized) {
-          MOZ_ASSERT(false,
-                     "Null principals require a spec URI in serialized JSON");
-          return nullptr;
-        }
-        rv = NS_NewURI(getter_AddRefs(uri), field.value);
-        NS_ENSURE_SUCCESS(rv, nullptr);
-        break;
-      case NullPrincipal::eSuffix:
-        bool ok = attrs.PopulateFromSuffix(field.value);
-        if (!ok) {
-          return nullptr;
-        }
-        break;
-    }
-  }
-
-  if (!uri) {
-    MOZ_ASSERT(false, "No URI deserialized");
-    return nullptr;
-  }
-
-  return NullPrincipal::Create(attrs, uri);
-}
-
 NS_IMETHODIMP
 NullPrincipal::GetPrecursorPrincipal(nsIPrincipal** aPrincipal) {
   *aPrincipal = nullptr;
@@ -331,3 +295,107 @@ NullPrincipal::GetPrecursorPrincipal(nsIPrincipal** aPrincipal) {
   contentPrincipal.forget(aPrincipal);
   return NS_OK;
 }
+
+bool NullPrincipalJSONHandler::startObject() {
+  switch (mState) {
+    case State::Init:
+      mState = State::StartObject;
+      break;
+    default:
+      NS_WARNING("Unexpected object value");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
+}
+
+bool NullPrincipalJSONHandler::propertyName(const JS::Latin1Char* name,
+                                            size_t length) {
+  switch (mState) {
+    case State::StartObject:
+    case State::AfterPropertyValue: {
+      if (length != 1) {
+        NS_WARNING(
+            nsPrintfCString("Unexpected property name length: %zu", length)
+                .get());
+        mState = State::Error;
+        return false;
+      }
+
+      char key = char(name[0]);
+      switch (key) {
+        case NullPrincipal::SpecKey:
+          mState = State::SpecKey;
+          break;
+        case NullPrincipal::SuffixKey:
+          mState = State::SuffixKey;
+          break;
+        default:
+          NS_WARNING(
+              nsPrintfCString("Unexpected property name: '%c'", key).get());
+          mState = State::Error;
+          return false;
+      }
+      break;
+    }
+    default:
+      NS_WARNING("Unexpected property name");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
+}
+
+bool NullPrincipalJSONHandler::endObject() {
+  switch (mState) {
+    case State::AfterPropertyValue:
+      MOZ_ASSERT(mUri);
+
+      mPrincipal = NullPrincipal::Create(mAttrs, mUri);
+      MOZ_ASSERT(mPrincipal);
+
+      mState = State::EndObject;
+      break;
+    default:
+      NS_WARNING("Unexpected end of object");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
+}
+
+bool NullPrincipalJSONHandler::stringValue(const JS::Latin1Char* str,
+                                           size_t length) {
+  switch (mState) {
+    case State::SpecKey: {
+      nsDependentCSubstring spec(reinterpret_cast<const char*>(str), length);
+      nsresult rv = NS_NewURI(getter_AddRefs(mUri), spec);
+      if (NS_FAILED(rv)) {
+        mState = State::Error;
+        return false;
+      }
+
+      mState = State::AfterPropertyValue;
+      break;
+    }
+    case State::SuffixKey: {
+      nsDependentCSubstring attrs(reinterpret_cast<const char*>(str), length);
+      if (!mAttrs.PopulateFromSuffix(attrs)) {
+        mState = State::Error;
+        return false;
+      }
+
+      mState = State::AfterPropertyValue;
+      break;
+    }
+    default:
+      NS_WARNING("Unexpected string value");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
+}

caps/NullPrincipal.h

@@ -21,9 +21,6 @@
 
 class nsIDocShell;
 class nsIURI;
-namespace Json {
-class Value;
-}
 
 #define NS_NULLPRINCIPAL_CID                         \
   {                                                  \
@@ -36,6 +33,8 @@ class Value;
 
 namespace mozilla {
 
+class JSONWriter;
+
 class NullPrincipal final : public BasePrincipal {
  public:
   static PrincipalKind Kind() { return eNullPrincipal; }
@@ -85,14 +84,15 @@ class NullPrincipal final : public BasePrincipal {
     return NS_OK;
   }
 
-  virtual nsresult PopulateJSONObject(Json::Value& aObject) override;
+  virtual nsresult WriteJSONInnerProperties(JSONWriter& aWriter) override;
 
   // Serializable keys are the valid enum fields the serialization supports
   enum SerializableKeys : uint8_t { eSpec = 0, eSuffix, eMax = eSuffix };
-  typedef mozilla::BasePrincipal::KeyValT<SerializableKeys> KeyVal;
 
-  static already_AddRefed<BasePrincipal> FromProperties(
-      nsTArray<NullPrincipal::KeyVal>& aFields);
+  static constexpr char SpecKey = '0';
+  static_assert(eSpec == 0);
+  static constexpr char SuffixKey = '1';
+  static_assert(eSuffix == 1);
 
   class Deserializer : public BasePrincipal::Deserializer {
    public:

caps/NullPrincipalJSONHandler.h

@@ -0,0 +1,91 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_NullPrincipalJSONHandler_h
+#define mozilla_NullPrincipalJSONHandler_h
+
+#include <stddef.h>  // size_t
+#include <stdint.h>  // uint32_t
+
+#include "js/TypeDecls.h"  // JS::Latin1Char
+
+#include "mozilla/AlreadyAddRefed.h"  // already_AddRefed
+#include "mozilla/Assertions.h"       // MOZ_ASSERT_UNREACHABLE
+#include "mozilla/RefPtr.h"           // RefPtr
+
+#include "nsCOMPtr.h"  // nsCOMPtr
+#include "nsDebug.h"   // NS_WARNING
+#include "nsIURI.h"    // nsIURI
+
+#include "NullPrincipal.h"
+#include "OriginAttributes.h"
+#include "SharedJSONHandler.h"
+
+namespace mozilla {
+
+// JSON parse handler for an inner object for NullPrincipal.
+// Used by PrincipalJSONHandler or SubsumedPrincipalJSONHandler.
+class NullPrincipalJSONHandler : public PrincipalJSONHandlerShared {
+  enum class State {
+    Init,
+
+    // After the inner object's '{'.
+    StartObject,
+
+    // After the property key for eSpec.
+    SpecKey,
+
+    // After the property key for eSuffix.
+    SuffixKey,
+
+    // After the property value for eSpec or eSuffix.
+    AfterPropertyValue,
+
+    // After the inner object's '}'.
+    EndObject,
+
+    Error,
+  };
+
+ public:
+  NullPrincipalJSONHandler() = default;
+  virtual ~NullPrincipalJSONHandler() = default;
+
+  virtual bool startObject() override;
+
+  using PrincipalJSONHandlerShared::propertyName;
+  virtual bool propertyName(const JS::Latin1Char* name, size_t length) override;
+
+  virtual bool endObject() override;
+
+  virtual bool startArray() override {
+    NS_WARNING("Unexpected array value");
+    mState = State::Error;
+    return false;
+  }
+  virtual bool endArray() override {
+    NS_WARNING("Unexpected array value");
+    mState = State::Error;
+    return false;
+  }
+
+  using PrincipalJSONHandlerShared::stringValue;
+  virtual bool stringValue(const JS::Latin1Char* str, size_t length) override;
+
+  bool HasAccepted() const { return mState == State::EndObject; }
+
+ protected:
+  virtual void SetErrorState() override { mState = State::Error; }
+
+ private:
+  State mState = State::Init;
+
+  nsCOMPtr<nsIURI> mUri;
+  OriginAttributes mAttrs;
+};
+
+}  // namespace mozilla
+
+#endif  // mozilla_NullPrincipalJSONHandler_h

caps/PrincipalJSONHandler.h

@@ -0,0 +1,116 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_PrincipalJSONHandler_h
+#define mozilla_PrincipalJSONHandler_h
+
+#include <stddef.h>  // size_t
+#include <stdint.h>  // uint32_t
+
+#include "js/JSON.h"       // JS::JSONParseHandler
+#include "js/TypeDecls.h"  // JS::Latin1Char
+
+#include "mozilla/AlreadyAddRefed.h"  // already_AddRefed
+#include "mozilla/RefPtr.h"           // RefPtr
+#include "mozilla/Variant.h"          // Variant
+
+#include "nsDebug.h"          // NS_WARNING
+#include "nsPrintfCString.h"  // nsPrintfCString
+
+#include "BasePrincipal.h"
+#include "ContentPrincipalJSONHandler.h"
+#include "ExpandedPrincipalJSONHandler.h"
+#include "NullPrincipalJSONHandler.h"
+#include "SharedJSONHandler.h"
+
+namespace mozilla {
+
+class PrincipalJSONHandlerTypes {
+ public:
+  enum class State {
+    Init,
+
+    // After top-level object's '{'.
+    StartObject,
+
+    // After the PrincipalKind property key for SystemPrincipal.
+    SystemPrincipal_Key,
+    // After the SystemPrincipal's inner object's '{'.
+    SystemPrincipal_StartObject,
+    // After the SystemPrincipal's inner object's '}'.
+    SystemPrincipal_EndObject,
+
+    // After the PrincipalKind property key for NullPrincipal, ContentPrincipal,
+    // or ExpandedPrincipal, and also the entire inner object.
+    // Delegates to mInnerHandler until the inner object's '}'.
+    NullPrincipal_Inner,
+    ContentPrincipal_Inner,
+    ExpandedPrincipal_Inner,
+
+    // After top-level object's '}'.
+    EndObject,
+
+    Error,
+  };
+
+  using InnerHandlerT =
+      Maybe<Variant<NullPrincipalJSONHandler, ContentPrincipalJSONHandler,
+                    ExpandedPrincipalJSONHandler>>;
+
+  static constexpr bool CanContainExpandedPrincipal = true;
+};
+
+// JSON parse handler for the top-level object for principal.
+//
+//                                 inner object
+//                                      |
+//       ---------------------------------------------------------
+//       |                                                       |
+// {"1": {"0": "https://mozilla.com", "2": "^privateBrowsingId=1"}}
+//   |
+//   |
+//   |
+// PrincipalKind
+//
+// For inner object except for the system principal case, this delegates
+// to NullPrincipalJSONHandler, ContentPrincipalJSONHandler, or
+// ExpandedPrincipalJSONHandler.
+//
+//// Null principal:
+// {"0":{"0":"moz-nullprincipal:{56cac540-864d-47e7-8e25-1614eab5155e}"}}
+//
+// Content principal:
+// {"1":{"0":"https://mozilla.com"}} -> {"0":"https://mozilla.com"}
+//
+// Expanded principal:
+// {"2":{"0":"<base64principal1>,<base64principal2>"}}
+//
+// System principal:
+// {"3":{}}
+class PrincipalJSONHandler
+    : public ContainerPrincipalJSONHandler<PrincipalJSONHandlerTypes> {
+  using State = PrincipalJSONHandlerTypes::State;
+  using InnerHandlerT = PrincipalJSONHandlerTypes::InnerHandlerT;
+
+ public:
+  PrincipalJSONHandler() = default;
+  virtual ~PrincipalJSONHandler() = default;
+
+  virtual void error(const char* msg, uint32_t line, uint32_t column) override {
+    NS_WARNING(
+        nsPrintfCString("JSON Error: %s at line %u column %u of the JSON data",
+                        msg, line, column)
+            .get());
+  }
+
+  already_AddRefed<BasePrincipal> Get() { return mPrincipal.forget(); }
+
+ protected:
+  virtual void SetErrorState() override { mState = State::Error; }
+};
+
+}  // namespace mozilla
+
+#endif  // mozilla_PrincipalJSONHandler_h

caps/SharedJSONHandler.h

@@ -0,0 +1,114 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_SharedJSONHandler_h
+#define mozilla_SharedJSONHandler_h
+
+#include "js/JSON.h"  // JS::JSONParseHandler
+
+#include "mozilla/RefPtr.h"  // RefPtr
+
+#include "BasePrincipal.h"  // BasePrincipal
+
+namespace mozilla {
+
+// Base class of all principal JSON parse handlers.
+class PrincipalJSONHandlerShared : public JS::JSONParseHandler {
+ public:
+  // Common handlers for inner objects.
+
+  // NOTE: propertyName and stringValue are partial overloads.
+  //       Subclasses should put the following:
+  //         * `using PrincipalJSONHandlerShared::propertyName`
+  //         * `using PrincipalJSONHandlerShared::stringValue`
+  virtual bool propertyName(const char16_t* name, size_t length) override {
+    NS_WARNING("Principal JSON shouldn't use non-ASCII");
+    SetErrorState();
+    return false;
+  };
+
+  virtual bool stringValue(const char16_t* str, size_t length) override {
+    NS_WARNING("Principal JSON shouldn't use non-ASCII");
+    SetErrorState();
+    return true;
+  }
+
+  virtual bool numberValue(double d) override {
+    NS_WARNING("Unexpected number value");
+    SetErrorState();
+    return false;
+  }
+
+  virtual bool booleanValue(bool v) override {
+    NS_WARNING("Unexpected boolean value");
+    SetErrorState();
+    return false;
+  }
+
+  virtual bool nullValue() override {
+    NS_WARNING("Unexpected null value");
+    SetErrorState();
+    return false;
+  }
+
+  virtual void error(const char* msg, uint32_t line, uint32_t column) override {
+    // Unused.
+  }
+
+ protected:
+  // Set to the error state for the above handlers.
+  virtual void SetErrorState() = 0;
+
+ public:
+  RefPtr<BasePrincipal> mPrincipal;
+};
+
+// Base class shared between PrincipalJSONHandler and
+// SubsumedPrincipalJSONHandler.
+// This implements the common code for them, absorbing the difference about
+// whether it can contain ExpandedPrincipal or not.
+template <typename HandlerTypesT>
+class ContainerPrincipalJSONHandler : public PrincipalJSONHandlerShared {
+  using State = typename HandlerTypesT::State;
+  using InnerHandlerT = typename HandlerTypesT::InnerHandlerT;
+  static constexpr bool CanContainExpandedPrincipal =
+      HandlerTypesT::CanContainExpandedPrincipal;
+
+ public:
+  // Common handlers.
+
+  virtual bool startObject() override;
+
+  using PrincipalJSONHandlerShared::propertyName;
+  virtual bool propertyName(const JS::Latin1Char* name, size_t length) override;
+  virtual bool endObject() override;
+
+  virtual bool startArray() override;
+
+  virtual bool endArray() override;
+
+  using PrincipalJSONHandlerShared::stringValue;
+  virtual bool stringValue(const JS::Latin1Char* str, size_t length) override;
+
+ private:
+  bool ProcessInnerResult(bool aResult);
+
+  template <class Func>
+  bool CallOnInner(Func&& aFunc) {
+    return mInnerHandler->match([&](auto& aInner) {
+      bool result = aFunc(aInner);
+      return ProcessInnerResult(result);
+    });
+  }
+
+ protected:
+  State mState = State::Init;
+
+  InnerHandlerT mInnerHandler;
+};
+
+}  // namespace mozilla
+
+#endif  // mozilla_SharedJSONHandler_h

caps/SubsumedPrincipalJSONHandler.h

@@ -0,0 +1,96 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_SubsumedPrincipalJSONHandler_h
+#define mozilla_SubsumedPrincipalJSONHandler_h
+
+#include <stddef.h>  // size_t
+#include <stdint.h>  // uint32_t
+
+#include "js/TypeDecls.h"  // JS::Latin1Char
+
+#include "mozilla/AlreadyAddRefed.h"  // already_AddRefed
+#include "mozilla/Variant.h"          // Variant
+#include "mozilla/RefPtr.h"           // RefPtr
+
+#include "nsDebug.h"  // NS_WARNING
+
+#include "BasePrincipal.h"
+#include "ContentPrincipalJSONHandler.h"
+#include "NullPrincipalJSONHandler.h"
+#include "SharedJSONHandler.h"
+
+namespace mozilla {
+
+class SubsumedPrincipalJSONHandlerTypes {
+ public:
+  enum class State {
+    Init,
+
+    // After the subsumed principal object's '{'.
+    StartObject,
+
+    // After the PrincipalKind property key for SystemPrincipal.
+    SystemPrincipal_Key,
+    // After the SystemPrincipal's inner object's '{'.
+    SystemPrincipal_StartObject,
+    // After the SystemPrincipal's inner object's '}'.
+    SystemPrincipal_EndObject,
+
+    // After the PrincipalKind property key for NullPrincipal or
+    // ContentPrincipal, and also the entire inner object.
+    // Delegates to mInnerHandler until the inner object's '}'.
+    //
+    // Unlike PrincipalJSONHandler, subsumed principal doesn't contain
+    // ExpandedPrincipal.
+    NullPrincipal_Inner,
+    ContentPrincipal_Inner,
+
+    // After the subsumed principal object's '}'.
+    EndObject,
+
+    Error,
+  };
+
+  using InnerHandlerT =
+      Maybe<Variant<NullPrincipalJSONHandler, ContentPrincipalJSONHandler>>;
+
+  static constexpr bool CanContainExpandedPrincipal = false;
+};
+
+// JSON parse handler for subsumed principal object inside ExpandedPrincipal's
+// new format.
+//
+//                       Subsumed principal object
+//                               |
+//              ----------------------------------
+//              |                                |
+// {"2": {"0": [{"1": {"0": https://mozilla.com"}}]}}
+//                |   |                         |
+//                |   ---------------------------
+//                |                |
+//                |         inner object
+//          PrincipalKind
+//
+// For inner object except for the system principal case, this delegates
+// to NullPrincipalJSONHandler or ContentPrincipalJSONHandler.
+class SubsumedPrincipalJSONHandler
+    : public ContainerPrincipalJSONHandler<SubsumedPrincipalJSONHandlerTypes> {
+  using State = SubsumedPrincipalJSONHandlerTypes::State;
+  using InnerHandlerT = SubsumedPrincipalJSONHandlerTypes::InnerHandlerT;
+
+ public:
+  SubsumedPrincipalJSONHandler() = default;
+  virtual ~SubsumedPrincipalJSONHandler() = default;
+
+  bool HasAccepted() const { return mState == State::EndObject; }
+
+ protected:
+  virtual void SetErrorState() override { mState = State::Error; }
+};
+
+}  // namespace mozilla
+
+#endif  // mozilla_SubsumedPrincipalJSONHandler_h

caps/SystemPrincipal.h

@@ -24,10 +24,6 @@
 
 class nsScriptSecurityManager;
 
-namespace Json {
-class Value;
-}
-
 namespace mozilla {
 
 class SystemPrincipal final : public BasePrincipal, public nsISerializable {

caps/tests/gtest/TestPrincipalSerialization.cpp

@@ -17,7 +17,7 @@ using mozilla::SystemPrincipal;
 // None of these tests work in debug due to assert guards
 #ifndef MOZ_DEBUG
 
-// calling toJson() twice with the same string arg
+// calling toJSON() twice with the same string arg
 // (ensure that we truncate correctly where needed)
 TEST(PrincipalSerialization, ReusedJSONArgument)
 {
@@ -46,28 +46,6 @@ TEST(PrincipalSerialization, ReusedJSONArgument)
   ASSERT_TRUE(JSON.EqualsLiteral("{\"1\":{\"0\":\"https://example.com/\"}}"));
 }
 
-// Assure that calling FromProperties() with an empty array list always returns
-// a nullptr The exception here is SystemPrincipal which doesn't have fields but
-// it also doesn't implement FromProperties These are overly cautious checks
-// that we don't try to create a principal in reality FromProperties is only
-// called with a populated array.
-TEST(PrincipalSerialization, FromPropertiesEmpty)
-{
-  nsTArray<ContentPrincipal::KeyVal> resContent;
-  nsCOMPtr<nsIPrincipal> contentPrincipal =
-      ContentPrincipal::FromProperties(resContent);
-  ASSERT_EQ(nullptr, contentPrincipal);
-
-  nsTArray<ExpandedPrincipal::KeyVal> resExpanded;
-  nsCOMPtr<nsIPrincipal> expandedPrincipal =
-      ExpandedPrincipal::FromProperties(resExpanded);
-  ASSERT_EQ(nullptr, expandedPrincipal);
-
-  nsTArray<NullPrincipal::KeyVal> resNull;
-  nsCOMPtr<nsIPrincipal> nullprincipal = NullPrincipal::FromProperties(resNull);
-  ASSERT_EQ(nullptr, nullprincipal);
-}
-
 // Double check that if we have two valid principals in a serialized JSON that
 // nullptr is returned
 TEST(PrincipalSerialization, TwoKeys)

devtools/client/aboutdebugging/test/browser/browser_aboutdebugging_serviceworker_not_compatible.js

@@ -115,8 +115,9 @@ add_task(async function testRemoteRuntime() {
 
 function assertWarningMessage(doc, expectedMessage) {
   const hasMessage = !!doc.querySelector(".qa-service-workers-warning");
-  ok(
-    hasMessage === expectedMessage,
+  Assert.strictEqual(
+    hasMessage,
+    expectedMessage,
     expectedMessage
       ? "Warning message is displayed"
       : "Warning message is not displayed"

devtools/client/aboutdebugging/test/browser/browser_aboutdebugging_serviceworker_runtime-page.js

@@ -45,8 +45,9 @@ add_task(async function () {
   await waitForServiceWorkerRunning(SW_URL, document);
 
   swPane = getDebugTargetPane("Service Workers", document);
-  ok(
-    swPane.querySelectorAll(".qa-debug-target-item").length === 1,
+  Assert.strictEqual(
+    swPane.querySelectorAll(".qa-debug-target-item").length,
+    1,
     "Service worker list has one element"
   );
   ok(

devtools/client/aboutdebugging/test/browser/helper-telemetry.js

@@ -47,8 +47,9 @@ function checkTelemetryEvents(expectedEvents, expectedSessionId) {
     const sameExtrasEvents = sameMethodEvents.filter(e =>
       _eventHasExpectedExtras(e, expectedEvent)
     );
-    ok(
-      sameExtrasEvents.length === 1,
+    Assert.strictEqual(
+      sameExtrasEvents.length,
+      1,
       "Found exactly one event matching the expected extras"
     );
     if (sameExtrasEvents.length === 0) {

devtools/client/application/test/browser/browser_application_panel_manifest-display.js

@@ -25,8 +25,9 @@ add_task(async function () {
   checkManifestMember(doc, "name", "Foo");
   checkManifestMember(doc, "background_color", "#ff0000");
 
-  ok(
-    doc.querySelector(".js-manifest-issues") === null,
+  Assert.strictEqual(
+    doc.querySelector(".js-manifest-issues"),
+    null,
     "No validation issues are being displayed"
   );
 
@@ -56,12 +57,16 @@ add_task(async function () {
   checkManifestMember(doc, "background_color", "");
 
   const issuesEl = doc.querySelector(".js-manifest-issues");
-  ok(issuesEl !== null, "Validation issues are displayed");
+  Assert.notStrictEqual(issuesEl, null, "Validation issues are displayed");
 
   const warningEl = [...issuesEl.querySelectorAll(".js-manifest-issue")].find(
     x => x.textContent.includes("background_color")
   );
-  ok(warningEl !== null, "A warning about background_color is displayed");
+  Assert.notStrictEqual(
+    warningEl,
+    null,
+    "A warning about background_color is displayed"
+  );
 
   // close the tab
   info("Closing the tab.");
@@ -83,12 +88,16 @@ add_task(async function () {
   ok(true, "Manifest is being displayed");
 
   const issuesEl = doc.querySelector(".js-manifest-issues");
-  ok(issuesEl !== null, "Validation issues are displayed");
+  Assert.notStrictEqual(issuesEl, null, "Validation issues are displayed");
 
   const errorEl = [...issuesEl.querySelectorAll(".js-manifest-issue")].find(x =>
     x.textContent.includes("JSON")
   );
-  ok(errorEl !== null, "An error about JSON parsing is displayed");
+  Assert.notStrictEqual(
+    errorEl,
+    null,
+    "An error about JSON parsing is displayed"
+  );
 
   // close the tab
   info("Closing the tab.");
@@ -111,9 +120,13 @@ add_task(async function () {
 
   // assert manifest icon is being displayed
   const iconEl = findMemberByLabel(doc, "128x128image/svg");
-  ok(iconEl !== null, "Icon label is being displayed with size and image type");
+  Assert.notStrictEqual(
+    iconEl,
+    null,
+    "Icon label is being displayed with size and image type"
+  );
   const imgEl = iconEl.querySelector(".js-manifest-item-content img");
-  ok(imgEl !== null, "An image is displayed for the icon");
+  Assert.notStrictEqual(imgEl, null, "An image is displayed for the icon");
   is(
     imgEl.src,
     URL_ROOT + "resources/manifest/icon.svg",

devtools/client/debugger/test/mochitest/browser_dbg-breakpoints-columns.js

@@ -44,7 +44,7 @@ async function enableFirstBreakpoint(dbg) {
   await addBreakpoint(dbg, "long.js", 32);
   const bpMarkers = await waitForAllElements(dbg, "columnBreakpoints");
 
-  ok(bpMarkers.length === 2, "2 column breakpoints");
+  Assert.strictEqual(bpMarkers.length, 2, "2 column breakpoints");
   assertClass(bpMarkers[0], "active");
   assertClass(bpMarkers[1], "active", false);
 }

devtools/client/debugger/test/mochitest/browser_dbg-breakpoints-cond-shortcut.js

@@ -123,7 +123,7 @@ async function enableFirstBreakpoint(dbg) {
   await addBreakpoint(dbg, "long.js", 32);
   const bpMarkers = await waitForAllElements(dbg, "columnBreakpoints");
 
-  ok(bpMarkers.length === 2, "2 column breakpoints");
+  Assert.strictEqual(bpMarkers.length, 2, "2 column breakpoints");
   assertClass(bpMarkers[0], "active");
   assertClass(bpMarkers[1], "active", false);
 }

devtools/client/debugger/test/mochitest/browser_dbg-breakpoints-debugger-statement.js

@@ -41,7 +41,7 @@ add_task(async function () {
 
   info("Enable the breakpoint for the second debugger statement on line 12");
   let bpElements = await waitForAllElements(dbg, "columnBreakpoints");
-  ok(bpElements.length === 2, "2 column breakpoints");
+  Assert.strictEqual(bpElements.length, 2, "2 column breakpoints");
   assertClass(bpElements[0], "active");
   assertClass(bpElements[1], "active", false);
 

devtools/client/debugger/test/mochitest/browser_dbg-chrome-create.js

@@ -37,7 +37,11 @@ add_task(async function () {
   );
 
   ok(process, "The remote debugger process was created");
-  ok(process.exitCode == null, "The remote debugger process is running");
+  Assert.equal(
+    process.exitCode,
+    null,
+    "The remote debugger process is running"
+  );
   is(
     typeof process.pid,
     "number",

devtools/client/debugger/test/mochitest/browser_dbg-editor-scroll.js

@@ -36,7 +36,11 @@ add_task(async function () {
   await waitForPaused(dbg);
   findElement(dbg, "frame", 1).focus();
   await clickElement(dbg, "frame", 1);
-  ok(cm.getScrollInfo().top != 0, "frame scrolled down to correct location");
+  Assert.notEqual(
+    cm.getScrollInfo().top,
+    0,
+    "frame scrolled down to correct location"
+  );
 
   info("Navigating while paused, goes to the correct location");
   await selectSource(dbg, "long.js");

devtools/client/debugger/test/mochitest/browser_dbg-pause-ux.js

@@ -44,7 +44,7 @@ add_task(async function () {
   );
 
   const matchScrollTop = getScrollTop(dbg);
-  ok(pauseScrollTop != matchScrollTop, "did not jump to debug line");
+  Assert.notEqual(pauseScrollTop, matchScrollTop, "did not jump to debug line");
 });
 
 function getScrollTop(dbg) {

devtools/client/debugger/test/mochitest/browser_dbg-reducer-cleanup-on-target-removal.js

@@ -52,11 +52,12 @@ add_task(async function () {
   await waitForSelectedSource(dbg, "bundle.js");
 
   // Assert that reducer do have some data before remove the target.
-  ok(dbg.selectors.getSourceCount() > 0, "Some sources exists");
+  Assert.greater(dbg.selectors.getSourceCount(), 0, "Some sources exists");
   is(dbg.selectors.getBreakpointCount(), 1, "There is one breakpoint");
   is(dbg.selectors.getSourceTabs().length, 2, "Two tabs are opened");
-  ok(
-    dbg.selectors.getAllThreads().length > 1,
+  Assert.greater(
+    dbg.selectors.getAllThreads().length,
+    1,
     "There is many targets/threads involved by the intergration test"
   );
   ok(
@@ -69,8 +70,9 @@ add_task(async function () {
     "The generated source is reporeted as selected"
   );
   ok(!!dbg.selectors.getFocusedSourceItem(), "Has a focused source tree item");
-  ok(
-    dbg.selectors.getExpandedState().size > 0,
+  Assert.greater(
+    dbg.selectors.getExpandedState().size,
+    0,
     "Has some expanded source tree items"
   );
 
@@ -86,20 +88,24 @@ add_task(async function () {
     "Some symbols for generated sources exists"
   );
   ok(!!Object.keys(state.ast.mutableInScopeLines).length, "Some scopes exists");
-  ok(
-    state.sourceActors.mutableSourceActors.size > 0,
+  Assert.greater(
+    state.sourceActors.mutableSourceActors.size,
+    0,
     "Some source actor exists"
   );
-  ok(
-    state.sourceActors.mutableBreakableLines.size > 0,
+  Assert.greater(
+    state.sourceActors.mutableBreakableLines.size,
+    0,
     "Some breakable line exists"
   );
-  ok(
-    state.sources.mutableBreakpointPositions.size > 0,
+  Assert.greater(
+    state.sources.mutableBreakpointPositions.size,
+    0,
     "Some breakable positions exists"
   );
-  ok(
-    state.sources.mutableOriginalBreakableLines.size > 0,
+  Assert.greater(
+    state.sources.mutableOriginalBreakableLines.size,
+    0,
     "Some original breakable lines exists"
   );
 

devtools/client/debugger/test/mochitest/browser_dbg-scopes-duplicated.js

@@ -153,10 +153,14 @@ add_task(async function () {
   let nodes = getAllLabels(dbg);
   const originalNodesCount = nodes.length;
   const targetNodeIndex = nodes.indexOf("target");
-  ok(targetNodeIndex > -1, "Found the target node");
+  Assert.greater(targetNodeIndex, -1, "Found the target node");
   await toggleScopeNode(dbg, targetNodeIndex);
   nodes = getAllLabels(dbg);
-  ok(nodes.length > originalNodesCount, "the target node was expanded");
+  Assert.greater(
+    nodes.length,
+    originalNodesCount,
+    "the target node was expanded"
+  );
   ok(nodes.includes("classList"), "classList is displayed");
 
   await resume(dbg);

devtools/client/debugger/test/mochitest/browser_dbg-scopes-xrays.js

@@ -63,5 +63,5 @@ function findNodeValue(dbg, text) {
 
 async function checkObjectNode(dbg, text, value) {
   await toggleNode(dbg, text);
-  ok(findNodeValue(dbg, "a") == value, "object value");
+  Assert.equal(findNodeValue(dbg, "a"), value, "object value");
 }

devtools/client/debugger/test/mochitest/browser_dbg-sourcemapped-toggle.js

@@ -23,7 +23,7 @@ add_task(async function () {
   invokeInTab("webpack3Babel6EsmodulesCjs");
   await waitForPaused(dbg);
 
-  ok(getOriginalScope(dbg) != null, "Scopes are now mapped");
+  Assert.notEqual(getOriginalScope(dbg), null, "Scopes are now mapped");
 
   ok(!findFooterNotificationMessage(dbg), "No footer notification message");
   await assertPreviewTextValue(dbg, 20, 20, {

devtools/client/debugger/test/mochitest/browser_dbg-step-in-uninitialized.js

@@ -23,8 +23,8 @@ add_task(async function test() {
 
   // We step past the 'let x' at the start of the function because it is not
   // a breakpoint position.
-  ok(findNodeValue(dbg, "x") == "undefined", "x undefined");
-  ok(findNodeValue(dbg, "y") == "(uninitialized)", "y uninitialized");
+  Assert.equal(findNodeValue(dbg, "x"), "undefined", "x undefined");
+  Assert.equal(findNodeValue(dbg, "y"), "(uninitialized)", "y uninitialized");
 
   await stepOver(dbg);
 
@@ -34,7 +34,7 @@ add_task(async function test() {
     9
   );
 
-  ok(findNodeValue(dbg, "y") == "3", "y initialized");
+  Assert.equal(findNodeValue(dbg, "y"), "3", "y initialized");
 });
 
 function findNodeValue(dbg, text) {

devtools/client/debugger/test/mochitest/browser_dbg-windowless-service-workers.js

@@ -7,7 +7,9 @@
 
 "use strict";
 
-const SW_URL = EXAMPLE_URL + "service-worker.sjs";
+// Use an URL with a specific port to check that Bug 1876533 is fixed
+// We're using URL without port in other tests, like browser_dbg-windowless-service-workers-reload.js
+const SW_URL = EXAMPLE_URL_WITH_PORT + "service-worker.sjs";
 
 add_task(async function () {
   info("Subtest #1");
@@ -15,7 +17,9 @@ add_task(async function () {
   await pushPref("devtools.debugger.threads-visible", true);
   await pushPref("dom.serviceWorkers.testing.enabled", true);
 
-  const dbg = await initDebugger("doc-service-workers.html");
+  const dbg = await initDebuggerWithAbsoluteURL(
+    EXAMPLE_URL_WITH_PORT + "doc-service-workers.html"
+  );
 
   invokeInTab("registerWorker");
   await waitForSource(dbg, "service-worker.sjs");
@@ -38,7 +42,7 @@ add_task(async function () {
   info("Subtest #2");
 
   const toolbox = await openNewTabAndToolbox(
-    `${EXAMPLE_URL}doc-service-workers.html`,
+    `${EXAMPLE_URL_WITH_PORT}doc-service-workers.html`,
     "jsdebugger"
   );
   const dbg = createDebuggerContext(toolbox);
@@ -73,7 +77,7 @@ add_task(async function () {
   info("Subtest #3");
 
   const toolbox = await openNewTabAndToolbox(
-    `${EXAMPLE_URL}doc-service-workers.html`,
+    `${EXAMPLE_URL_WITH_PORT}doc-service-workers.html`,
     "jsdebugger"
   );
   const dbg = createDebuggerContext(toolbox);
@@ -84,10 +88,14 @@ add_task(async function () {
 
   const firstTab = gBrowser.selectedTab;
 
-  await addTab(`${EXAMPLE_URL}service-worker.sjs?setStatus=newServiceWorker`);
+  await addTab(
+    `${EXAMPLE_URL_WITH_PORT}service-worker.sjs?setStatus=newServiceWorker`
+  );
   await removeTab(gBrowser.selectedTab);
 
-  const secondTab = await addTab(`${EXAMPLE_URL}doc-service-workers.html`);
+  const secondTab = await addTab(
+    `${EXAMPLE_URL_WITH_PORT}doc-service-workers.html`
+  );
 
   await gBrowser.selectTabAtIndex(gBrowser.tabs.indexOf(firstTab));
   await checkAdditionalThreadCount(dbg, 2);
@@ -111,7 +119,7 @@ add_task(async function () {
   await removeTab(secondTab);
 
   // Reset the SJS in case we will be repeating the test.
-  await addTab(`${EXAMPLE_URL}service-worker.sjs?setStatus=`);
+  await addTab(`${EXAMPLE_URL_WITH_PORT}service-worker.sjs?setStatus=`);
   await removeTab(gBrowser.selectedTab);
 });
 
@@ -124,7 +132,7 @@ add_task(async function () {
   }
 
   const toolbox = await openNewTabAndToolbox(
-    `${EXAMPLE_URL}doc-service-workers.html`,
+    `${EXAMPLE_URL_WITH_PORT}doc-service-workers.html`,
     "jsdebugger"
   );
   const dbg = createDebuggerContext(toolbox);

devtools/client/debugger/test/mochitest/browser_dbg-windowless-workers.js

@@ -15,7 +15,7 @@ add_task(async function () {
 
   await waitForThreadCount(dbg, 2);
   const workers = dbg.selectors.getThreads();
-  ok(workers.length == 2, "Got two workers");
+  Assert.equal(workers.length, 2, "Got two workers");
   const thread1 = workers[0].actor;
   const thread2 = workers[1].actor;
 
@@ -43,7 +43,7 @@ add_task(async function () {
   await addExpression(dbg, "count");
   is(getWatchExpressionLabel(dbg, 1), "count");
   const v = getWatchExpressionValue(dbg, 1);
-  ok(v == `${+v}`, "Value of count should be a number");
+  Assert.equal(v, `${+v}`, "Value of count should be a number");
 
   info("StepOver in the first worker");
   await stepOver(dbg);

devtools/client/debugger/test/mochitest/browser_dbg-worker-nested.js

@@ -11,5 +11,5 @@ add_task(async function () {
 
   await waitForThreadCount(dbg, 2);
   const workers = dbg.selectors.getThreads();
-  ok(workers.length == 2, "Got two workers");
+  Assert.equal(workers.length, 2, "Got two workers");
 });

devtools/client/debugger/test/mochitest/browser_dbg-worker-scopes.js

@@ -22,22 +22,22 @@ add_task(async function () {
   assertPausedAtSourceAndLine(dbg, workerSource2.id, 11);
 
   await toggleNode(dbg, "var_array");
-  ok(findNodeValue(dbg, "0") == '"mango"', "array elem0");
-  ok(findNodeValue(dbg, "1") == '"pamplemousse"', "array elem1");
-  ok(findNodeValue(dbg, "2") == '"pineapple"', "array elem2");
+  Assert.equal(findNodeValue(dbg, "0"), '"mango"', "array elem0");
+  Assert.equal(findNodeValue(dbg, "1"), '"pamplemousse"', "array elem1");
+  Assert.equal(findNodeValue(dbg, "2"), '"pineapple"', "array elem2");
   await toggleNode(dbg, "var_array");
 
   await toggleNode(dbg, "var_tarray");
-  ok(findNodeValue(dbg, "0") == "42", "tarray elem0");
-  ok(findNodeValue(dbg, "1") == "43", "tarray elem1");
-  ok(findNodeValue(dbg, "2") == "44", "tarray elem2");
+  Assert.equal(findNodeValue(dbg, "0"), "42", "tarray elem0");
+  Assert.equal(findNodeValue(dbg, "1"), "43", "tarray elem1");
+  Assert.equal(findNodeValue(dbg, "2"), "44", "tarray elem2");
   await toggleNode(dbg, "var_tarray");
 
   await toggleNode(dbg, "var_set");
   await toggleNode(dbg, "<entries>");
 
-  ok(findNodeValue(dbg, "0") == '"papaya"', "set elem0");
-  ok(findNodeValue(dbg, "1") == '"banana"', "set elem1");
+  Assert.equal(findNodeValue(dbg, "0"), '"papaya"', "set elem0");
+  Assert.equal(findNodeValue(dbg, "1"), '"banana"', "set elem1");
   await toggleNode(dbg, "var_set");
 
   await toggleNode(dbg, "var_map");

devtools/client/debugger/test/mochitest/head.js

@@ -19,6 +19,9 @@ const EXAMPLE_URL =
 const EXAMPLE_REMOTE_URL =
   "https://example.org/browser/devtools/client/debugger/test/mochitest/examples/";
 
+const EXAMPLE_URL_WITH_PORT =
+  "http://mochi.test:8888/browser/devtools/client/debugger/test/mochitest/examples/";
+
 // shared-head.js handles imports, constants, and utility functions
 Services.scriptloader.loadSubScript(
   "chrome://mochitests/content/browser/devtools/client/shared/test/shared-head.js",

devtools/client/dom/test/browser_dom_array.js

@@ -60,7 +60,11 @@ add_task(async function () {
       i++,
       `index ${name} is correct and sorted into the correct position`
     );
-    ok(typeof row.name === "number", "array index is displayed as a number");
+    Assert.strictEqual(
+      typeof row.name,
+      "number",
+      "array index is displayed as a number"
+    );
     is(TEST_ARRAY[name], row.value, `value for array[${name}] is ${row.value}`);
   }
 });

devtools/client/dom/test/browser_dom_nodes_select.js

@@ -22,7 +22,7 @@ add_task(async function () {
   const inspector = toolbox.getPanel("inspector");
 
   const openInInspectorIcon = node.querySelector(".open-inspector");
-  ok(node !== null, "Node was logged as expected");
+  Assert.notStrictEqual(node, null, "Node was logged as expected");
 
   info(
     "Clicking on the inspector icon and waiting for the " +

devtools/client/framework/test/browser_tab_descriptor_fission.js

@@ -52,8 +52,9 @@ add_task(async function () {
     null,
     "With Fission or server side target switching, example.com target front is destroyed"
   );
-  ok(
-    comTabTarget != newTarget,
+  Assert.notEqual(
+    comTabTarget,
+    newTarget,
     "With Fission or server side target switching, a new target was created for example.org"
   );
 

devtools/client/framework/test/browser_toolbox_hosts_size.js

@@ -38,8 +38,9 @@ add_task(async function () {
   );
 
   iframe.style.height = "10000px"; // Set height to something unreasonably large.
-  ok(
-    iframe.clientHeight < panelHeight,
+  Assert.less(
+    iframe.clientHeight,
+    panelHeight,
     `The iframe fits within the available space (${iframe.clientHeight} < ${panelHeight})`
   );
 
@@ -54,8 +55,9 @@ add_task(async function () {
 
   const oldWidth = iframe.style.width;
   iframe.style.width = "10000px"; // Set width to something unreasonably large.
-  ok(
-    iframe.clientWidth < panelWidth,
+  Assert.less(
+    iframe.clientWidth,
+    panelWidth,
     `The iframe fits within the available space (${iframe.clientWidth} < ${panelWidth})`
   );
   iframe.style.width = oldWidth;

devtools/client/framework/test/browser_toolbox_meatball.js

@@ -26,8 +26,9 @@ add_task(async function () {
   const menuDockToBottom = toolbox.doc.getElementById(
     "toolbox-meatball-menu-dock-bottom"
   );
-  ok(
-    menuDockToBottom.getAttribute("aria-checked") === "true",
+  Assert.strictEqual(
+    menuDockToBottom.getAttribute("aria-checked"),
+    "true",
     "menuDockToBottom has checked"
   );
 

devtools/client/framework/test/browser_toolbox_options_disable_js.js

@@ -115,8 +115,9 @@ async function testJSDisabled() {
     const output = doc.getElementById("output");
     doc.querySelector("#logJSDisabled").click();
 
-    ok(
-      output.textContent !== "JavaScript Disabled",
+    Assert.notStrictEqual(
+      output.textContent,
+      "JavaScript Disabled",
       'output is not "JavaScript Disabled"'
     );
   });
@@ -131,8 +132,9 @@ async function testJSDisabledIframe() {
     const iframeDoc = iframe.contentDocument;
     const output = iframeDoc.getElementById("output");
     iframeDoc.querySelector("#logJSDisabled").click();
-    ok(
-      output.textContent !== "JavaScript Disabled",
+    Assert.notStrictEqual(
+      output.textContent,
+      "JavaScript Disabled",
       'output is not "JavaScript Disabled" in iframe'
     );
   });

devtools/client/framework/test/browser_toolbox_telemetry_activate_splitconsole.js

@@ -95,7 +95,7 @@ async function checkResults() {
     const expected = DATA[i];
 
     // ignore timestamp
-    ok(timestamp > 0, "timestamp is greater than 0");
+    Assert.greater(timestamp, 0, "timestamp is greater than 0");
     is(category, expected.category, "category is correct");
     is(method, expected.method, "method is correct");
     is(object, expected.object, "object is correct");

devtools/client/framework/test/browser_toolbox_telemetry_enter.js

@@ -136,7 +136,7 @@ async function checkResults() {
     const expected = DATA[i];
 
     // ignore timestamp
-    ok(timestamp > 0, "timestamp is greater than 0");
+    Assert.greater(timestamp, 0, "timestamp is greater than 0");
     is(category, expected.category, "category is correct");
     is(method, expected.method, "method is correct");
     is(object, expected.object, "object is correct");

devtools/client/framework/test/browser_toolbox_telemetry_exit.js

@@ -113,7 +113,7 @@ async function checkResults() {
     const expected = DATA[i];
 
     // ignore timestamp
-    ok(timestamp > 0, "timestamp is greater than 0");
+    Assert.greater(timestamp, 0, "timestamp is greater than 0");
     is(category, expected.category, "category is correct");
     is(method, expected.method, "method is correct");
     is(object, expected.object, "object is correct");

devtools/client/framework/test/browser_toolbox_toolbar_overflow_button_visibility.js

@@ -44,8 +44,9 @@ add_task(async function () {
   const initialTabCount = toolbox.doc.querySelectorAll(".devtools-tab").length;
   // Make all toolbox button to be visible.
   setToolboxButtonsVisibility(checkButtons, true);
-  ok(
-    toolbox.doc.querySelectorAll(".devtools-tab").length < initialTabCount,
+  Assert.less(
+    toolbox.doc.querySelectorAll(".devtools-tab").length,
+    initialTabCount,
     "Count of shown devtools tab should decreased"
   );
 

devtools/client/framework/test/browser_toolbox_zoom_popup.js

@@ -78,8 +78,16 @@ add_task(async function () {
           // vertical: IntID::ContextMenuOffsetVertical of macOS uses -6.
           const xDelta = Math.abs(menuBounds.left - buttonBounds.left);
           const yDelta = Math.abs(menuBounds.top - buttonBounds.bottom);
-          ok(xDelta < 2, "xDelta is lower than 2: " + xDelta + ". #" + menu.id);
-          ok(yDelta < 6, "yDelta is lower than 6: " + yDelta + ". #" + menu.id);
+          Assert.less(
+            xDelta,
+            2,
+            "xDelta is lower than 2: " + xDelta + ". #" + menu.id
+          );
+          Assert.less(
+            yDelta,
+            6,
+            "yDelta is lower than 6: " + yDelta + ". #" + menu.id
+          );
         }
         break;
 
@@ -90,8 +98,9 @@ add_task(async function () {
           const buttonCenter = buttonBounds.left + buttonBounds.width / 2;
           const arrowCenter = arrowBounds.left + arrowBounds.width / 2;
           const delta = Math.abs(arrowCenter - buttonCenter);
-          ok(
-            Math.round(delta) <= 1,
+          Assert.lessOrEqual(
+            Math.round(delta),
+            1,
             "Center of arrow is within 1px of button center" +
               ` (delta: ${delta})`
           );

devtools/client/inspector/animation/test/browser_animation_animation-timeline-tick.js

@@ -41,9 +41,9 @@ add_task(async function () {
   info("Checking timeline tick item elements after enlarge sidebar width");
   await setSidebarWidth("100%", inspector);
   await assertTickLabels(timeScale, listContainerEl);
-  ok(
-    timelineTickItemLength <
-      listContainerEl.querySelectorAll(".tick-label").length,
+  Assert.less(
+    timelineTickItemLength,
+    listContainerEl.querySelectorAll(".tick-label").length,
     "The timeline tick item elements should increase"
   );
 });

devtools/client/inspector/animation/test/browser_animation_current-time-scrubber_each-different-creation-time-animations.js

@@ -25,9 +25,9 @@ add_task(async function () {
 
   info("Check existed animations have different currentTime");
   const animations = animationInspector.state.animations;
-  ok(
-    animations[0].state.currentTime + WAIT_TIME >
-      animations[1].state.currentTime,
+  Assert.greater(
+    animations[0].state.currentTime + WAIT_TIME,
+    animations[1].state.currentTime,
     `The currentTime of added animation shold be ${WAIT_TIME}ms less than ` +
       "at least that currentTime of first animation"
   );

devtools/client/inspector/animation/test/browser_animation_infinity-duration_current-time-scrubber.js

@@ -32,8 +32,9 @@ add_task(async function () {
   const barBounds = barEl.getBoundingClientRect();
   const barX = barBounds.x + barBounds.width / 2 - controllerBounds.x;
   const expectedBarX = controllerBounds.width * 0.5;
-  ok(
-    Math.abs(barX - expectedBarX) < 1,
+  Assert.less(
+    Math.abs(barX - expectedBarX),
+    1,
     "Progress bar should indicate at progress of 0.5"
   );
 });

devtools/client/inspector/animation/test/browser_animation_pause-resume-button_end-time.js

@@ -60,8 +60,9 @@ function assertPlayState(animations, expectedState) {
 
 function assertCurrentTimeLessThanDuration(animations) {
   animations.forEach((animation, index) => {
-    ok(
-      animation.state.currentTime < animation.state.duration,
+    Assert.less(
+      animation.state.currentTime,
+      animation.state.duration,
       `The current time of animation[${index}] should be less than its duration`
     );
   });
@@ -70,8 +71,9 @@ function assertCurrentTimeLessThanDuration(animations) {
 function assertScrubberPosition(panel) {
   const scrubberEl = panel.querySelector(".current-time-scrubber");
   const marginInlineStart = parseFloat(scrubberEl.style.marginInlineStart);
-  ok(
-    marginInlineStart >= 0,
+  Assert.greaterOrEqual(
+    marginInlineStart,
+    0,
     "The translateX of scrubber position should be zero or more"
   );
 }

devtools/client/inspector/animation/test/browser_animation_timing_negative-playback-rate_current-time-scrubber.js

@@ -23,15 +23,16 @@ add_task(async function () {
     animationInspector,
     animationInspector.state.timeScale.getDuration() * 0.5
   );
-  ok(
-    initialCurrentTime >
-      animationInspector.state.animations[0].state.currentTime,
+  Assert.greater(
+    initialCurrentTime,
+    animationInspector.state.animations[0].state.currentTime,
     "currentTime should be decreased"
   );
 
   info("Check whether the progress bar was moved to left");
-  ok(
-    initialProgressBarX > getProgressBarX(panel),
+  Assert.greater(
+    initialProgressBarX,
+    getProgressBarX(panel),
     "Progress bar should be moved to left"
   );
 });

devtools/client/inspector/animation/test/head.js

@@ -1023,8 +1023,9 @@ function checkAdjustingTheTime(animation1, animation2) {
     animation2.currentTime / animation2.playbackRate -
     animation1.currentTime / animation1.playbackRate;
   const createdTimeDiff = animation1.createdTime - animation2.createdTime;
-  ok(
-    Math.abs(adjustedCurrentTimeDiff - createdTimeDiff) < 0.1,
+  Assert.less(
+    Math.abs(adjustedCurrentTimeDiff - createdTimeDiff),
+    0.1,
     "Adjusted time is correct"
   );
 }

devtools/client/inspector/changes/test/browser_changes_background_tracking.js

@@ -42,5 +42,5 @@ add_task(async function () {
   const sym = Symbol();
   const onTimeout = wait(500).then(() => sym);
   const raceResult = await Promise.any([onResetChanges, onTimeout]);
-  ok(raceResult === sym, "RESET_CHANGES has not been dispatched");
+  Assert.strictEqual(raceResult, sym, "RESET_CHANGES has not been dispatched");
 });

devtools/client/inspector/flexbox/test/browser_flexbox_item_outline_rotates_for_column.js

@@ -27,7 +27,7 @@ add_task(async function () {
 
   // Check that the outline is wider than it is tall in the configuration.
   let bounds = flexOutline.getBoxQuads()[0].getBounds();
-  ok(bounds.width > bounds.height, "The outline looks like a row");
+  Assert.greater(bounds.width, bounds.height, "The outline looks like a row");
 
   // Select a flex item in the column flexbox layout.
   onFlexItemOutlineRendered = waitForDOM(
@@ -45,5 +45,9 @@ add_task(async function () {
 
   // Check that the outline is taller than it is wide in the configuration.
   bounds = flexOutline.getBoxQuads()[0].getBounds();
-  ok(bounds.height > bounds.width, "The outline looks like a column");
+  Assert.greater(
+    bounds.height,
+    bounds.width,
+    "The outline looks like a column"
+  );
 });

devtools/client/inspector/fonts/test/browser_fontinspector_input-element-used-font.js

@@ -14,9 +14,10 @@ add_task(async function () {
   await selectNode(".input-field", inspector);
 
   const fontEls = getUsedFontsEls(viewDoc);
-  ok(fontEls.length == 1, `Used fonts found for styled input element`);
-  ok(
-    fontEls[0].textContent == "Ostrich Sans Medium",
+  Assert.equal(fontEls.length, 1, `Used fonts found for styled input element`);
+  Assert.equal(
+    fontEls[0].textContent,
+    "Ostrich Sans Medium",
     `Proper font found: 'Ostrich Sans Medium' for styled input.`
   );
 });

devtools/client/inspector/markup/test/browser_markup_dragdrop_autoscroll_01.js

@@ -29,7 +29,7 @@ add_task(async function () {
   });
 
   const bottomScrollPos = await waitForScrollStop(markup.doc);
-  ok(bottomScrollPos > 0, "The view was scrolled down");
+  Assert.greater(bottomScrollPos, 0, "The view was scrolled down");
 
   info("Simulate a mousemove at the top and expect more scrolling");
 
@@ -40,7 +40,7 @@ add_task(async function () {
   });
 
   const topScrollPos = await waitForScrollStop(markup.doc);
-  ok(topScrollPos < bottomScrollPos, "The view was scrolled up");
+  Assert.less(topScrollPos, bottomScrollPos, "The view was scrolled up");
   is(topScrollPos, 0, "The view was scrolled up to the top");
 
   info("Simulate a mouseup to stop dragging");

devtools/client/inspector/markup/test/browser_markup_dragdrop_autoscroll_02.js

@@ -28,7 +28,7 @@ add_task(async function () {
   });
 
   const bottomScrollPos = await waitForScrollStop(markup.doc);
-  ok(bottomScrollPos > 0, "The view was scrolled down");
+  Assert.greater(bottomScrollPos, 0, "The view was scrolled down");
   info("Simulate a mousemove at the top and expect more scrolling");
 
   markup._onMouseMove({
@@ -38,7 +38,7 @@ add_task(async function () {
   });
 
   const topScrollPos = await waitForScrollStop(markup.doc);
-  ok(topScrollPos < bottomScrollPos, "The view was scrolled up");
+  Assert.less(topScrollPos, bottomScrollPos, "The view was scrolled up");
   is(topScrollPos, 0, "The view was scrolled up to the top");
 
   info("Simulate a mouseup to stop dragging");

devtools/client/inspector/markup/test/browser_markup_mutation_01.js

@@ -197,8 +197,9 @@ const TEST_DATA = [
       const container = await getContainerForSelector("#node1", inspector);
       ok(!container.inlineTextChild, "Does not have single text child.");
       ok(container.canExpand, "Can expand container with child nodes.");
-      ok(
-        container.editor.elt.querySelector(".text") == null,
+      Assert.equal(
+        container.editor.elt.querySelector(".text"),
+        null,
         "Single text child editor removed."
       );
     },
@@ -229,8 +230,9 @@ const TEST_DATA = [
       const container = await getContainerForSelector("#node1", inspector);
       ok(!container.inlineTextChild, "Does not have single text child.");
       ok(!container.canExpand, "Can't expand empty container.");
-      ok(
-        container.editor.elt.querySelector(".text") == null,
+      Assert.equal(
+        container.editor.elt.querySelector(".text"),
+        null,
         "Single text child editor removed."
       );
     },

devtools/client/inspector/markup/test/browser_markup_node_names.js

@@ -19,16 +19,18 @@ add_task(async function () {
     inspector
   );
   info("Checking the clipPath element");
-  ok(
-    clipPathContainer.editor.tag.textContent === "clipPath",
+  Assert.strictEqual(
+    clipPathContainer.editor.tag.textContent,
+    "clipPath",
     "clipPath node name is not lowercased"
   );
 
   const divContainer = await getContainerForSelector("div", inspector);
 
   info("Checking the div element");
-  ok(
-    divContainer.editor.tag.textContent === "div",
+  Assert.strictEqual(
+    divContainer.editor.tag.textContent,
+    "div",
     "div node name is lowercased"
   );
 });

devtools/client/inspector/markup/test/browser_markup_node_names_namespaced.js

@@ -35,8 +35,9 @@ add_task(async function () {
     inspector
   );
   info("Checking the clipPath element");
-  ok(
-    clipPathContainer.editor.tag.textContent === "svg:clipPath",
+  Assert.strictEqual(
+    clipPathContainer.editor.tag.textContent,
+    "svg:clipPath",
     "svg:clipPath node is correctly displayed"
   );
 
@@ -45,8 +46,9 @@ add_task(async function () {
     inspector
   );
   info("Checking the circle element");
-  ok(
-    circlePathContainer.editor.tag.textContent === "svg:circle",
+  Assert.strictEqual(
+    circlePathContainer.editor.tag.textContent,
+    "svg:circle",
     "svg:circle node is correctly displayed"
   );
 });

devtools/client/inspector/markup/test/browser_markup_shadowdom_slotted_keyboard_focus.js

@@ -64,8 +64,9 @@ add_task(async function () {
   EventUtils.synthesizeKey("KEY_Tab", {}, win);
   await tagFocused;
 
-  ok(
-    inspector.markup.doc.activeElement === tagSpan,
+  Assert.strictEqual(
+    inspector.markup.doc.activeElement,
+    tagSpan,
     "Focus has gone back to first element"
   );
 });

devtools/client/inspector/markup/test/browser_markup_toggle_closing_tag_line.js

@@ -38,8 +38,9 @@ add_task(async function () {
   const iframe = await getNodeFront("iframe", inspector);
   const { nodes } = await inspector.walker.children(iframe);
   const documentFront = nodes[0];
-  ok(
-    documentFront.displayName === "#document",
+  Assert.strictEqual(
+    documentFront.displayName,
+    "#document",
     "First child of IFRAME is #document"
   );
 

devtools/client/inspector/markup/test/browser_markup_void_elements_html.js

@@ -16,8 +16,9 @@ add_task(async function () {
     !editor.elt.classList.contains("void-element"),
     "h1 element does not have void-element class"
   );
-  ok(
-    !editor.elt.querySelector(".close").style.display !== "none",
+  Assert.notStrictEqual(
+    !editor.elt.querySelector(".close").style.display,
+    "none",
     "h1 element tag is not hidden"
   );
 
@@ -29,7 +30,11 @@ add_task(async function () {
   );
   let closeElement = container.editor.elt.querySelector(".close");
   let computedStyle = win.getComputedStyle(closeElement);
-  ok(computedStyle.display === "none", "img closing tag is hidden");
+  Assert.strictEqual(
+    computedStyle.display,
+    "none",
+    "img closing tag is hidden"
+  );
 
   info("check void element with pseudo element");
   const hrNodeFront = await getNodeFront("hr.before", inspector);
@@ -40,12 +45,16 @@ add_task(async function () {
   );
   closeElement = container.editor.elt.querySelector(".close");
   computedStyle = win.getComputedStyle(closeElement);
-  ok(computedStyle.display === "none", "hr closing tag is hidden");
+  Assert.strictEqual(computedStyle.display, "none", "hr closing tag is hidden");
 
   info("check expanded void element closing tag is not hidden");
   await inspector.markup.expandNode(hrNodeFront);
   await waitForMultipleChildrenUpdates(inspector);
   ok(container.expanded, "hr container is expanded");
   computedStyle = win.getComputedStyle(closeElement);
-  ok(computedStyle.display === "none", "hr closing tag is not hidden anymore");
+  Assert.strictEqual(
+    computedStyle.display,
+    "none",
+    "hr closing tag is not hidden anymore"
+  );
 });

devtools/client/inspector/markup/test/browser_markup_void_elements_xhtml.js

@@ -16,8 +16,9 @@ add_task(async function () {
     !editor.elt.classList.contains("void-element"),
     "h1 element does not have void-element class"
   );
-  ok(
-    !editor.elt.querySelector(".close").style.display !== "none",
+  Assert.notStrictEqual(
+    !editor.elt.querySelector(".close").style.display,
+    "none",
     "h1 element tag is not hidden"
   );
 
@@ -29,5 +30,9 @@ add_task(async function () {
   );
   const closeElement = container.editor.elt.querySelector(".close");
   const computedStyle = win.getComputedStyle(closeElement);
-  ok(computedStyle.display !== "none", "br closing tag is not hidden");
+  Assert.notStrictEqual(
+    computedStyle.display,
+    "none",
+    "br closing tag is not hidden"
+  );
 });

devtools/client/inspector/markup/test/helper_events_test_runner.js

@@ -175,8 +175,9 @@ async function checkEventsForNode(test, inspector) {
     const shouldBeDisabled =
       expected[i].attributes?.includes("React") ||
       expected[i].attributes?.includes("jQuery");
-    ok(
-      disabled === shouldBeDisabled,
+    Assert.strictEqual(
+      disabled,
+      shouldBeDisabled,
       `The checkbox is ${shouldBeDisabled ? "disabled" : "enabled"}\n`
     );
 

devtools/client/inspector/rules/test/browser_rules_completion-new-property_multiline.js

@@ -60,7 +60,7 @@ add_task(async function () {
 
   info("Check that UP/DOWN navigates in the input, even when next to a number");
   EventUtils.synthesizeKey("VK_DOWN", {}, view.styleWindow);
-  ok(editor.input.selectionStart !== pos, "Input caret moved");
+  Assert.notStrictEqual(editor.input.selectionStart, pos, "Input caret moved");
   is(editor.input.value, LONG_CSS_VALUE, "Input value was not decremented.");
 
   info("Move the caret to the end of the gradient definition.");

devtools/client/inspector/rules/test/browser_rules_container-queries.js

@@ -184,9 +184,9 @@ function assertContainerQueryData(view, expectedRules) {
         expectedRule.ancestorRulesData.join("\n"),
         `Expected ancestor rules data displayed for ${selector}`
       );
-      ok(
-        ancestorDataEl.querySelector(".container-query .open-inspector") !==
-          null,
+      Assert.notStrictEqual(
+        ancestorDataEl.querySelector(".container-query .open-inspector"),
+        null,
         "An icon is displayed to select the container in the markup view"
       );
     }